publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2020-04-07 | Nonreciprocal Dzyaloshinskii-Moriya magnetoacoustic waves | We study the interaction of surface acoustic waves with spin waves in
ultra-thin CoFeB/Pt bilayers. Due to the interfacial Dzyaloshinskii-Moriya
interaction (DMI), the spin wave dispersion is non-degenerate for oppositely
propagating spin waves in CoFeB/Pt. In combination with the additional
nonreciprocity of the magne... | 2004.03535v2 |
2021-04-05 | Optical Damage Threshold and THz Generation Efficiency of (Fe,CoFeB)/(Ta,Pt) Spintronic Emitters | THz pulses are generated from femtosecond pulse-excited
ferromagnetic/nonmagnetic spintronic heterostructures via inverse spin Hall
effect. The contribution from ultrafast demagnetization/remagnetization is
extremely weak, in the comparison. The highest possible THz signal strength
from spintronic THz emitters is limit... | 2104.02028v1 |
2023-02-14 | Direct evidence of terahertz emission arising from anomalous Hall effect | A detailed understanding of the different mechanisms being responsible for
terahertz (THz) emission in ferromagnetic (FM) materials will aid in designing
efficient THz emitters. In this report, we present direct evidence of THz
emission from single layer Co$_{0.4}$Fe$_{0.4}$B$_{0.2}$ (CoFeB) FM thin films.
The dominant... | 2302.07398v2 |
2023-03-21 | Inducing or suppressing the anisotropy in multilayers based on CoFeB | Controlling the uniaxial magnetic anisotropy is of practical interest to a
wide variety of applications. We study Co$_{40}$Fe$_{40}$B$_{20}$ single films
grown on various crystalline orientations of LiNbO$_3$ substrates and on
oxidized silicon. We identify the annealing conditions that are appropriate to
induce or supp... | 2303.11718v1 |
2023-06-19 | Spin transport and magnetic proximity effect in CoFeB/normal metal/Pt trilayers | We present a study of the damping and spin pumping properties of CoFeB/X/Pt
systems with $\rm X=Al,Cr$ and $\rm Ta$. We show that the total damping of the
CoFeB/Pt systems is strongly reduced when an interlayer is introduced
independently of the material. Using a model that considers spin relaxation, we
identify the or... | 2306.11009v2 |
2023-11-09 | Magnon-phonon coupling of synthetic antiferromagnets in a surface acoustic wave cavity resonator | We use a surface acoustic wave (SAW) cavity resonator to study the coupling
of acoustic magnons in a synthetic antiferromagnet (SAF) and the phonons
carried by SAWs. The SAF is composed of a CoFeB/Ru/CoFeB trilayer and the
scattering matrix of the SAW resonator is studied to assess the coupling. We
find that the spectr... | 2311.05275v1 |
2024-01-15 | Multiple Frequency Steps in Synthetic Antiferromagnet Based Double Spin Josephson Junctions Using CoFeB and Fe3Sn | Superconducting quantum interference device (SQUID) which is made of two
parallel Josephson junctions has applications in magnetometry. A similar
spin-based device is proposed here where spin superfluid in ferromagnet (FM)
mimics the superconducting state. Two materials CoFeB and Fe3Sn are used for
spin superfluid-base... | 2401.08005v1 |
2008-01-09 | Current-induced magnetization switching in MgO barrier magnetic tunnel junctions with CoFeB based synthetic ferrimagnetic free layers | We investigated the effect of using a synthetic ferrimagnetic (SyF) free
layer in MgO-based magnetic tunnel junctions (MTJs) on current-induced
magnetization switching (CIMS), particularly for application to spin-transfer
torque random access memory (SPRAM). The employed SyF free layer had a
Co40Fe40B20/ Ru/ Co40Fe40B2... | 0801.1355v1 |
2012-07-11 | Layer thickness dependence of the current induced effective field vector in Ta|CoFeB|MgO | The role of current induced effective magnetic field in ultrathin magnetic
heterostructures is increasingly gaining interest since it can provide
efficient ways of manipulating magnetization electrically. Two effects, known
as the Rashba spin orbit field and the spin Hall spin torque, have been
reported to be responsib... | 1207.2521v1 |
2013-05-12 | Spin Pumping and Inverse Spin Hall Effect in Germanium | We have measured the inverse spin Hall effect (ISHE) in \textit{n}-Ge at room
temperature. The spin current in germanium was generated by spin pumping from a
CoFeB/MgO magnetic tunnel junction in order to prevent the impedance mismatch
issue. A clear electromotive force was measured in Ge at the ferromagnetic
resonance... | 1305.2602v1 |
2017-03-10 | Room-temperature perpendicular magnetization switching through giant spin-orbit torque from sputtered BixSe(1-x) topological insulator material | The spin-orbit torque (SOT) arising from materials with large spin-orbit
coupling promises a path for ultra-low power and fast magnetic-based storage
and computational devices. We investigated the SOT from magnetron-sputtered
BixSe(1-x) thin films in BixSe(1-x)/CoFeB heterostructures by using a dc planar
Hall method. R... | 1703.03822v1 |
2019-07-08 | Bloch-to-Néel domain wall transition evinced through morphology of magnetic bubble expansion in Ta/CoFeB/MgO layers | Ta/CoFeB/MgO trilayers with perpendicular magnetic anisotropy are often
characterised by vanishing or modest values of interfacial
Dzyaloshinskii-Moriya interaction (DMI), which results in purely Bloch or mixed
Bloch-N\'eel domain walls (DWs). Here we investigate the creep evolution of the
overall magnetic bubble morph... | 1907.03708v1 |
2019-07-14 | Current-Induced magnetization switching by the high spin Hall conductivity $α$-W | The spin Hall effect originating from 5d heavy transition metal thin films
such as Pt, Ta, and W is able to generate efficient spin-orbit torques that can
switch adjacent magnetic layers. This mechanism can serve as an alternative to
conventional spin-transfer torque for controlling next-generation magnetic
memories. A... | 1907.06192v1 |
2019-10-02 | A Low Temperature Functioning CoFeB/MgO Based Perpendicular Magnetic Tunnel Junction for Cryogenic Nonvolatile Random Access Memory | We investigated the low temperature performance of CoFeB/MgO based
perpendicular magnetic tunnel junctions (pMTJs) by characterizing their
quasi-static switching voltage, high speed pulse write error rate and endurance
down to 9 K. pMTJ devices exhibited high magnetoresistance (>120%) and reliable
(error rate<10-4) bi-... | 1910.01149v1 |
2018-02-22 | Correlation of tunnel magnetoresistance with the magnetic properties in perpendicular CoFeB-based junctions with exchange bias | We investigate the dependence of magnetic properties on the post-annealing
temperature/time, the thickness of soft ferromagnetic electrode and Ta dusting
layer in the pinned electrode as well as their correlation with the tunnel
magnetoresistance ratio, in a series of perpendicular magnetic tunnel junctions
of material... | 1802.08002v2 |
2020-04-07 | Laser-induced magnetization precession in individual magnetoelastic domains of a multiferroic CoFeB/BaTiO$_3$ composite | Using a magneto-optical pump-probe technique with micrometer spatial
resolution we show that magnetization precession can be launched in individual
magnetic domains imprinted in a Co$_{40}$Fe$_{40}$B$_{20}$ (CoFeB) layer by
elastic coupling to ferroelectric domains in a BaTiO$_{3}$ substrate. The
dependence of the prec... | 2004.03566v5 |
2018-04-11 | Thermographic measurements of spin-current-induced temperature modulation in metallic bilayers | Spin-to-heat current conversion effects have been investigated in bilayer
films consisting of a paramagnetic metal (PM; Pt, W, or Ta) and a ferromagnetic
metal (FM; CoFeB or permalloy). When a charge current is applied to the PM/FM
bilayer film, a spin current is generated across the PM/FM interface owing to
the spin H... | 1804.04068v1 |
2019-09-20 | Field-free spin-orbit torque switching through domain wall motion | Deterministic current-induced spin-orbit torque (SOT) switching of
magnetization in a heavy transition metal/ferromagnetic metal/oxide magnetic
heterostructure with the ferromagnetic layer being perpendicularly-magnetized
typically requires an externally-applied in-plane field to break the switching
symmetry. We show t... | 1909.09604v1 |
2019-12-16 | Spin-current manipulation of photoinduced magnetization dynamics in heavy metal / ferromagnet double layer based nanostructures | Spin currents offer a way to control static and dynamic magnetic properties,
and therefore they are crucial for next-generation MRAM devices or spin-torque
oscillators. Manipulating the dynamics is especially interesting within the
context of photo-magnonics. In typical $3d$ transition metal ferromagnets like
CoFeB, th... | 1912.07728v1 |
2019-12-20 | Atomistic investigation of the temperature and size dependence of the energy barrier of CoFeB/MgO nanodots | The balance between low power consumption and high efficiency in memory
devices is a major limiting factor in the development of new technologies.
Magnetic random access memories (MRAM) based on CoFeB/MgO magnetic tunnel
junctions (MTJs) have been proposed as candidates to replace the current
technology due to their no... | 1912.09761v1 |
2020-07-06 | Transverse and Longitudinal Spin-Torque Ferromagnetic Resonance for Improved Measurements of Spin-Orbit Torques | Spin-torque ferromagnetic resonance (ST-FMR) is a common method used to
measure spin-orbit torques (SOTs) in heavy metal/ferromagnet bilayer
structures. In the course of a measurement, other resonant processes such as
spin pumping (SP) and heating can cause spin current or heat flows between the
layers, inducing additi... | 2007.02850v1 |
2020-12-10 | Pulse-width and Temperature Dependence of Memristive Spin-Orbit Torque Switching | It is crucial that magnetic memory devices formed from magnetic
heterostructures possess sizable spin-orbit torque (SOT) efficiency and high
thermal stability to realize both efficient SOT control and robust storage of
such memory devices. However, most previous studies on various types of
magnetic heterostructures hav... | 2012.05531v1 |
2021-02-06 | Spin pumping and inverse spin Hall effect in CoFeB/IrMn heterostructures | High spin to charge conversion efficiency is the requirement for the
spintronics devices which is governed by spin pumping and inverse spin Hall
effect (ISHE). In last one decade, ISHE and spin pumping are heavily
investigated in ferromagnet/ heavy metal (HM) heterostructures. Recently
antiferromagnetic (AFM) materials... | 2102.03624v2 |
2021-06-10 | Spin-Orbit Torque Engineering in β-W/CoFeB Heterostructures via Ta and V Alloying at Interfaces | Spin-orbit torque manifested as an accumulated spin-polarized moment at
nonmagnetic normal metal, and ferromagnet interfaces is a promising
magnetization switching mechanism for spintronic devices. To fully exploit this
in practice, materials with a high spin Hall angle, i.e., a charge-to-spin
conversion efficiency, ar... | 2106.05460v1 |
2022-11-04 | Exchange energies in CoFeB/Ru/CoFeB Synthetic Antiferromagnets | The interlayer exchange coupling confers specific properties to Synthetic
Antiferromagnets that make them suitable for several applications of
spintronics. The efficient use of this magnetic configuration requires an
in-depth understanding of the magnetic properties and their correlation with
the material structure. He... | 2211.02497v1 |
2023-06-29 | Ultrafast THz probing of nonlocal orbital current in transverse multilayer metallic heterostructures | THz generation from femtosecond photoexcited spintronic heterostructures has
recently become a versatile tool for investigating ultrafast spin-transport and
transient charge-current in a non-contact and non-invasive manner. The same
from the orbital effects is still in the primitive stage. Here, we
experimentally demon... | 2306.17027v2 |
2008-06-20 | Penetration Depth of Transverse Spin Current in Ferromagnetic Metals | The line width of the ferromagnetic resonance (FMR) spectrum of
Cu/CoFeB/Cu/Co/Cu is studied. Analyzing the FMR spectrum by the theory of spin
pumping, we determined the penetration depth of the transverse spin current in
the Co layer. The obtained penetration depth of Co is 1.7 nm. | 0806.3315v1 |
2019-11-08 | Room Temperature Spin to Charge Conversion in Amorphous Topological Insulating Gd-Alloyed BixSe1-x/CoFeB Bilayers | Disordered topological insulator (TI) films have gained intense interest by
benefiting from both the TIs exotic transport properties and the advantage of
mass production by sputtering. Here, we report on the clear evidence of
spin-charge conversion (SCC) in amorphous Gd-alloyed BixSe1-x (BSG)/CoFeB
bilayers fabricated ... | 1911.03323v12 |
2022-08-10 | Enhancement of Spin-Charge Conversion Efficiency for Co$_{3}$Sn$_{2}$S$_{2}$ across Transition from Paramagnetic to Ferromagnetic Phase | Co$_{3}$Sn$_{2}$S$_{2}$ (CSS) is one of the shandite compounds and becomes a
magnetic Weyl semimetal candidate below the ferromagnetic phase transition
temperature ($\textit{T}_\textrm{C}$). In this paper, we investigate the
temperature ($\textit{T}$) dependence of conversion between charge current and
spin current for... | 2208.05394v1 |
2023-11-10 | Observation by SANS and PNR of pure Néel-type domain wall profiles and skyrmion suppression below room temperature in magnetic [Pt/CoFeB/Ru]$_{10}$ multilayers | We report investigations of the magnetic textures in periodic [Pt(1
nm)/(CoFeB(0.8 nm)/Ru(1.4 nm)]$_{10}$ multilayers using polarised neutron
reflectometry (PNR) and small-angle neutron scattering (SANS). The multilayers
are known to host skyrmions stabilized by Dzyaloshinskii-Moriya interactions
induced by broken inve... | 2311.05959v2 |
2007-12-17 | Spin tunneling in junctions with disordered ferromagnets | We provide compelling evidence to establish that, contrary to one's
elementary guess, the tunneling spin polarization (TSP) of amorphous CoFeB is
larger than that of highly textured fcc CoFeB. First principles atomic and
electronic structure calculations reveal striking agreement between the
measured TSP and the predic... | 0712.2722v1 |
2011-03-22 | Inductive determination of the optimum tunnel barrier thickness in magnetic tunnelling junction stacks for spin torque memory applications | We use pulsed inductive microwave magnetometry to study the precessional
magnetization dynamics of the free layer in CoFeB/MgO/CoFeB based magnetic
tunnelling junction stacks with varying MgO barrier thickness. From the field
dependence of the precession frequency we are able to derive the uniaxial
anisotropy energy an... | 1103.4248v1 |
2011-06-03 | Origin of in-plane uniaxial magnetic anisotropy in CoFeB amorphous ferromagnetic thin-films | Describing the origin of uniaxial magnetic anisotropy (UMA) is generally
problematic in systems other than single crystals. We demonstrate an in-plane
UMA in amorphous CoFeB films on GaAs(001) which has the expected symmetry of
the interface anisotropy in ferromagnetic films on GaAs(001), but strength
which is independ... | 1106.0606v1 |
2012-05-13 | Voltage-Induced Ferromagnetic Resonance in Magnetic Tunnel Junctions | We demonstrate excitation of ferromagnetic resonance in CoFeB/MgO/CoFeB
magnetic tunnel junctions (MTJs) by the combined action of voltage-controlled
magnetic anisotropy (VCMA) and spin transfer torque (ST). Our measurements
reveal that GHz-frequency VCMA torque and ST in low-resistance MTJs have
similar magnitudes, an... | 1205.2835v2 |
2012-08-08 | Spin transfer torque devices utilizing the giant spin Hall effect of tungsten | We report a giant spin Hall effect (SHE) in {\beta}-W thin films. Using spin
torque induced ferromagnetic resonance with a {\beta}-W/CoFeB bilayer
microstrip we determine the spin Hall angle to be |\theta|=0.30\pm0.02, large
enough for an in-plane current to efficiently reverse the orientation of an
in-plane magnetized... | 1208.1711v1 |
2013-03-19 | X-ray absorption spectroscopy and magnetic circular dichroism studies of L1_0-Mn-Ga thin films | Tetragonally distorted \(\rm{Mn}_{3-x}\rm{Ga}_x\) thin films with \(0.1< x <
2\) show a strong perpendicular magnetic anisotropy and low magnetization and
thus have the potential to serve as electrodes in spin transfer torque magnetic
random access memory. Because a direct capping of these films with MgO is
problematic... | 1303.4648v2 |
2013-05-27 | Magnetization reversal in sub-100nm magnetic tunnel junctions with ultrathin MgO barrier biased along hard axis | We report on room temperature magnetoresistance and low frequency noise in
sub-100nm elliptic CoFeB/MgO/CoFeB magnetic tunnel junctions with ultrathin
(0.9nm) barriers. For magnetic fields applied along the hard axis, we observe
current induced magnetization switching between the antiparallel and parallel
alignments at... | 1305.6209v1 |
2013-05-29 | Enhanced interface perpendicular magnetic anisotropy in Ta|CoFeB|MgO using nitrogen doped Ta underlayers | We show that the magnetic characteristics of Ta|CoFeB|MgO magnetic
heterostructures are strongly influenced by doping the Ta underlayer with
nitrogen. In particular, the saturation magnetization drops upon doping the Ta
underlayer, suggesting that the doped underlayer acts as a boron diffusion
barrier. In addition, the... | 1305.6660v1 |
2013-08-08 | Interface control of the magnetic chirality in TaN|CoFeB|MgO heterosctructures | Recent advances in the understanding of spin orbital effects in ultrathin
magnetic heterostructures have opened new paradigms to control magnetic moments
electrically. The Dzyaloshinskii-Moriya interaction (DMI) is said to play a key
role in forming a Neel-type domain wall that can be driven by the spin Hall
torque, a ... | 1308.1751v1 |
2013-10-18 | Quantitative characterization of the spin orbit torque using harmonic Hall voltage measurements | Solid understanding of current induced torques is key to the development of
current and voltage controlled magnetization dynamics in ultrathin magnetic
heterostructures. To evaluate the size and direction of such torques, or
effective fields, a number of methods have been employed. Here we examine the
adiabatic (low fr... | 1310.4879v1 |
2013-12-03 | Depth dependent magnetization profiles of hybrid exchange springs | We report on the magnetization depth profile of a hybrid exchange spring
system in which a Co/Pd multilayer with perpendicular anisotropy is coupled to
a CoFeB thin film with in-plane anisotropy. The competition between these two
orthogonal anisotropies promotes a strong depth dependence of the magnetization
orientatio... | 1312.0878v1 |
2014-04-04 | Angular and temperature dependence of current induced spin-orbit effective fields in Ta/CoFeB/MgO nanowires | Current induced spin-orbit effective magnetic fields in
metal/ferromagnet/oxide trilayers provide a new way to manipulate the
magnetization, which is an alternative to the conventional current induced spin
transfer torque arising from noncollinear magnetization. Ta/CoFeB/MgO
structures are expected to be useful for non... | 1404.1130v1 |
2014-04-08 | Ferromagnetic resonance spin pumping in CoFeB with highly resistive non-magnetic electrodes | The relative contribution of spin pumping and spin rectification from the
ferromagnetic resonance of CoFeB/non-magnetic bilayers was investigated as a
function of non-magnetic electrode resistance. Samples with highly resistive
electrodes of Ta or Ti exhibit a stronger spin rectification signal, which may
result in ove... | 1404.1993v1 |
2014-05-02 | Spin-orbit torque-driven magnetization switching and thermal effects studied in Ta\CoFeB\MgO nanowires | We demonstrate magnetization switching in out-of-plane magnetized
Ta\CoFeB\MgO nanowires by current pulse injection along the nanowires, both
with and without a constant and uniform magnetic field collinear to the current
direction. We deduce that an effective torque arising from spin-orbit effects
in the multilayer dr... | 1405.0452v1 |
2014-05-08 | Controlling boron redistribution in CoFeB/MgO magnetic tunnel junctions during annealing by variation of cap layer materials and MgO deposition methods | Magnetic tunnel junctions with crystalline MgO tunnel barrier and amorphous
CoFeB electrodes received much attention due to their high tunnel magneto
resistance ratio at room temperature. One important parameter for achieving
high tunnel magneto resistance ratios is to control the boron diffusion from
the electrodes es... | 1405.1907v1 |
2014-07-30 | Room Temperature Spin Pumping in Topological Insulator Bi2Se3 | Three-dimensional (3D) topological insulators are known for their strong
spin-orbit coupling and the existence of spin-textured topological surface
states which could be potentially exploited for spintronics. Here, we
investigate spin pumping from a metallic ferromagnet (CoFeB) into a 3D
topological insulator (Bi2Se3) ... | 1407.7940v1 |
2014-11-18 | Towards wafer scale inductive characterization of spin transfer torque critical current density of magnetic tunnel junction stacks | We explore the prospects of wafer scale inductive probing of the critical
current density $j^{c0}$ for spin transfer torque switching of a
CoFeB/MgO/CoFeB magnetic tunnel junction with varying MgO thickness. From
inductive measurements magnetostatic parameters and the effective damping are
derived and $j^{c0}$ is calcu... | 1411.4868v1 |
2015-04-25 | Magnetic phase transitions in Ta/CoFeB/MgO multilayers | We study thin films and magnetic tunnel junction nanopillars based on
Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO multilayers by electrical transport and
magnetometry measurements. These measurements suggest that an ultrathin
magnetic oxide layer forms at the Co$_{20}$Fe$_{60}$B$_{20}$/MgO interface. At
approximately 160 K, the ... | 1504.06716v1 |
2015-05-21 | Resistance minimum and electrical conduction mechanism in polycrystalline CoFeB thin films | The temperature dependent resistance $R$($T$) of polycrystalline
ferromagnetic CoFeB thin films of varying thickness are analyzed considering
various electrical scattering processes. We observe a resistance minimum in
$R$($T$) curves below $\simeq$ 29 K, which can be explained as an effect of
intergranular Coulomb inte... | 1505.05711v2 |
2015-08-04 | Scanning Kerr microscopy of current induced switching in Ta/CoFeB/MgO films with perpendicular magnetic anisotropy | Ta/CoFeB/MgO trilayers with perpendicular magnetic anisotropy are expected to
play a key role in the next generation of current and electric field switched
memory and logic devices. In this study we use Kerr microscopy alongside
electrical transport measurement to gain insight into the underlying switching
mechanisms o... | 1508.00833v2 |
2015-10-16 | Enhanced orbital magnetic moments in magnetic heterostructures with interface perpendicular magnetic anisotropy | We have studied the magnetic layer thickness dependence of the orbital
magnetic moment in magnetic heterostructures to identify contributions from
interfaces. Three different heterostructures, Ta/CoFeB/MgO, Pt/Co/AlO$_x$ and
Pt/Co/Pt, which possess significant interface contribution to the perpendicular
magnetic anisot... | 1510.04756v1 |
2015-12-02 | Dynamic cantilever magnetometry of individual CoFeB nanotubes | We investigate single CoFeB nanotubes with hexagonal cross-section using
dynamic cantilever magnetometry (DCM). We develop both an analytical model
based on the Stoner-Wohlfarth approximation and a broadly applicable numerical
framework for analyzing DCM measurements of magnetic nanostructures.
Magnetometry data show t... | 1512.00621v1 |
2016-04-10 | Interfacial Dzyaloshinskii-Moriya interaction in Pt/CoFeB films: effect of the heavy-metal thickness | We report the observation of a Pt layer thickness dependence on the induced
interfacial Dzyaloshinskii-Moriya interaction in ultra-thin
Pt($d_{\text{Pt}}$)/CoFeB films. Taking advantage of the large spin-orbit
coupling of the heavy metal, the interfacial Dzyaloshinskii-Moriya interaction
is quantified by Brillouin ligh... | 1604.02626v2 |
2016-04-14 | THz-driven ultrafast spin-lattice scattering in amorphous metallic ferromagnets | We use single-cycle THz fields and the femtosecond magneto-optical Kerr
effect to respectively excite and probe the magnetization dynamics in two
thin-film ferromagnets with different lattice structure: crystalline Fe and
amorphous CoFeB. We observe Landau-Lifshitz-torque magnetization dynamics of
comparable magnitude ... | 1604.04077v1 |
2016-04-26 | Comparison of laser induced and intrinsic tunnel magneto-Seebeck effect in CoFeB/MgAl$_2$O$_4$ and CoFeB/MgO magnetic tunnel junctions | We present a comparison of the tunnel magneto-Seebeck effect for laser
induced and intrinsic heating. Therefore,
Co$_{40}$Fe$_{40}$B$_{20}$/MgAl$_2$O$_4$ and Co$_{25}$Fe$_{55}$B$_{20}$/MgO
magnetic tunnel junctions have been prepared. The TMS ratio of 3\,\% in case of
the MAO MTJ agrees well with ratios found for other... | 1604.07569v2 |
2016-05-23 | Direct measurement of interfacial Dzyaloshinskii-Moriya interaction in X/CoFeB/MgO heterostructures with a scanning-NV magnetometer | The Dzyaloshinskii-Moriya Interaction (DMI) has recently attracted
considerable interest owing to its fundamental role in the stabilization of
chiral spin textures in ultrathin ferromagnets, which are interesting
candidates for future spintronic technologies. Here we employ a scanning
nano-magnetometer based on a singl... | 1605.07044v1 |
2016-07-21 | Effect of annealing on the interfacial Dzyaloshinskii-Moriya interaction in Ta/CoFeB/MgO trilayers | The interfacial Dzyaloshinskii-Moriya interaction (DMI) has been shown to
stabilize homochiral N\'eel-type domain walls in thin films with perpendicular
magnetic anisotropy and as a result permit them to be propagated by a spin Hall
torque. In this study, we demonstrate that in Ta/Co$_{20}$Fe$_{60}$B$_{20}$/MgO
the DMI... | 1607.06405v1 |
2017-07-26 | Reorientable Spin Direction for Spin Current Produced by the Anomalous Hall Effect | We show experimentally that the spin direction of the spin current generated
by spin-orbit interactions within a ferromagnetic layer can be reoriented by
turning the magnetization direction of this layer. We do this by measuring the
field-like component of spin-orbit torque generated by an exchange-biased FeGd
thin fil... | 1707.08631v1 |
2017-11-30 | Domain Wall Motion Driven by Laplace Pressure in CoFeB-MgO Nanodots with Perpendicular Anisotropy | We have studied the magnetization reversal of CoFeB-MgO nanodots with
perpendicular anisotropy for size ranging from w=400 nm to 1 {\mu}m. Contrary
to previous experiments, the switching field distribution is shifted toward
lower magnetic fields as the size of the elements is reduced with a mean
switching field varying... | 1711.11334v2 |
2018-03-08 | CMOS compatible W/CoFeB/MgO spin Hall nano-oscillators with wide frequency tunability | We demonstrate low-operational-current W/Co$_{20}$Fe$_{60}$B$_{20}$/MgO spin
Hall nano-oscillators (SHNOs) on highly resistive silicon (HiR-Si) substrates.
Thanks to a record high spin Hall angle of the $\beta$-phase W ($\theta_{SH}$ =
-0.53), a very low threshold current density of 3.3 $\times$ 10$^{7}$ A/cm$^2$
can b... | 1803.03032v1 |
2018-06-13 | Enhanced Spin-Orbit Torques and Magnetization Switching through Interface Engineering | The origin of spin-orbit torques generated from the conversion of
charge-to-spin currents is of considerable debate. Solid understanding of the
physics behind is key to the development of current and voltage controlled
switching dynamics in ultrathin heterostuctures. The field free switching
observed recently (Phys. Re... | 1806.05163v1 |
2018-06-20 | Domain wall resistance in CoFeB-based heterostructures with interface Dzyaloshinskii-Moriya interaction | We have studied the domain wall resistance in W/Ta/CoFeB/MgO
heterostructures. The Ta layer thickness is varied to control the type of
domain walls via changes in the interfacial Dzyaloshinskii Moriya interaction.
We find a nearly constant domain wall resistance against the Ta layer
thickness. Adding contributions from... | 1806.07750v1 |
2018-11-13 | Spin-orbit torques acting upon a perpendicularly-magnetized Py layer | We show that Py, a commonly-used soft ferromagnetic material with weak
anisotropy, can become perpendicularly-magnetized while depositing on Ta buffer
layer with Hf or Zr insertion layers (ILs) and MgO capping layer. By using two
different approaches, namely harmonic voltage measurement and hysteresis loop
shift measur... | 1811.05164v1 |
2017-04-01 | Thermally nucleated magnetic reversal in CoFeB/MgO nanodots | Power consumption is the main limitation in the development of new high
performance random access memory for portable electronic devices. Magnetic RAM
(MRAM) with CoFeB/MgO based magnetic tunnel junctions (MTJs) is a promising
candidate for reducing the power consumption given its non-volatile nature
while achieveing h... | 1704.00106v1 |
2017-05-13 | Tuning the perpendicular magnetic anisotropy, spin Hall switching current density and domain wall velocity by submonolayer insertion in Ta / CoFeB / MgO heterostructures | By submonolayer insertion of Au, Pt, or Pd into Ta / CoFeB / MgO / Ta
heterostructures we tune the perpendicular magnetic anisotropy and the coercive
field of the ferromagnetic layer. We demonstrate that this has a major
influence on the spin Hall switching current density and its dependence on the
external magnetic fi... | 1705.04800v1 |
2019-10-17 | Planar Hall driven torque in a FM/NM/FM system | An important goal of spintronics is to covert a charge current into a spin
current with a controlled spin polarization that can exert torques on an
adjacent magnetic layer. Here we demonstrate such torques in a two ferromagnet
system. A CoNi multilayer is used as a spin current source in a sample with
structure CoNi/Au... | 1910.08039v1 |
2019-06-14 | Mechanisms of FMR line broadening in CoFeB-LiNbO$_3$ granular films in the vicinity of metal-insulator transition | Metal-insulator (CoFeB)$_x$(LiNbO$_3$)$_{100-x}$ nanocomposite films with
different content of the ferromagnetic (FM) phase $x$ are investigated by
ferromagnetic resonance (FMR) technique. A strong change of the FMR line shape
is observed in the vicinity of metal-insulator transition (MIT) of the film,
where the hoppin... | 1906.06320v2 |
2020-04-03 | Modulation of field-like spin orbit torque in heavy metal / ferromagnet heterostructure | Recent studies rediscovered the crucial role of field-like spin orbit torque
(SOT) in nanosecond-timescale SOT dynamics. However, there is not yet an
effective way to control its relative amplitude. Here, we experimentally
modulate the field-like SOT in W/CoFeB/MgO trilayers through tuning the
interfacial spin accumula... | 2004.01357v1 |
2020-04-29 | Terahertz Emission From an Exchange-Coupled Synthetic Antiferromagnet | We report on terahertz emission from FeMnPt/Ru/FeMnPt and
Pt/CoFeB/Ru/CoFeB/Pt synthetic antiferromagnet (SAF) structures upon
irradiation by a femtosecond laser; the former is via the anomalous Hall
effect, whereas the latter is through the inverse spin Hall effect. The
antiparallel alignment of the two ferromagnetic ... | 2004.14128v1 |
2020-05-11 | Improving thermal stability of MnN/CoFeB exchange bias systems by optimizing the Ta buffer layer | We investigated the influence of the Ta buffer layer on the thermal stability
of polycrystalline Ta/ MnN/ CoFeB exchange bias systems, showing high exchange
bias of about 1800 Oe at room temperature. The thermal stability of those
trilayer systems is limited by nitrogen diffusion that occurs during annealing
processes.... | 2005.05166v1 |
2017-02-24 | Giant perpendicular exchange bias with antiferromagnetic MnN | We investigated an out-of-plane exchange bias system that is based on the
antiferromagnet MnN. Polycrystalline, highly textured film stacks of Ta / MnN /
CoFeB / MgO / Ta were grown on SiO$_x$ by (reactive) magnetron sputtering and
studied by x-ray diffraction and Kerr magnetometry. Nontrivial modifications of
the exch... | 1702.07538v2 |
2019-05-22 | Reduced Exchange Interactions in Magnetic Tunnel Junction Free Layers with Insertion Layers | Perpendicularly magnetized CoFeB layers with ultra-thin non-magnetic
insertion layers are very widely used as the electrodes in magnetic tunnel
junctions for spin transfer magnetic random access memory devices. Exchange
interactions play a critical role in determining the thermal stability of
magnetic states in such de... | 1905.09329v1 |
2019-08-06 | Superparamagnetic dwell times and tuning of switching rates in perpendicular CoFeB/MgO/CoFeB tunnel junctions | Thin electrodes of magnetic tunnel junctions can show superparamagnetism at
surprisingly low temperature. We analysed their thermally induced switching for
varying temperature, magnetic and electric field. Although the dwell times
follow an Arrhenius law, they are orders of magnitude too small compared to a
model of si... | 1908.02139v3 |
2019-09-06 | Effect of Tantalum spacer thickness and deposition conditions on the properties of MgO/CoFeB/Ta/CoFeB/MgO free layers | To get stable perpendicularly magnetized tunnel junctions at small device
dimensions, composite free layers that comprise two MgO/FeCoB interfaces as
sources of interface anisotropy are generally used. Proper cristallisation and
annealing robustness is typically ensured by the insertion of a spacer layer of
the early t... | 1909.02741v1 |
2020-02-16 | Electric-field control of spin-orbit torques in perpendicularly magnetized W/CoFeB/MgO films | Controlling magnetism by electric fields offers a highly attractive
perspective for designing future generations of energy-efficient information
technologies. Here, we demonstrate that the magnitude of current-induced
spin-orbit torques in thin perpendicularly magnetized CoFeB films can be tuned
and even increased by e... | 2002.06578v1 |
2020-10-31 | Effect of spin glass frustration on exchange bias in NiMn/CoFeB bilayers | Exchange bias in ferromagnetic/antiferromagnetic systems can be explained in
terms of various interfacial phenomena. Among these spin glass frustration can
affect the magnetic properties in exchange bias systems. Here we have studied a
NiMn/CoFeB exchange bias system in which spin glass frustration seems to play a
cruc... | 2011.00188v1 |
2021-01-18 | Magnetization switching induced by spin-orbit torque from Co2MnGa magnetic Weyl semimetal thin films | This study reports the magnetization switching induced by spin-orbit torque
(SOT) from the spin current generated in Co2MnGa magnetic Weyl semimetal (WSM)
thin films. We deposited epitaxial Co2MnGa thin films with highly B2-ordered
structure on MgO(001) substrates. The SOT was characterized by harmonic Hall
measurement... | 2101.06881v1 |
2021-02-07 | Spinterface Induced Modification in Magnetic Properties in Co40Fe40B20/Fullerene Bilayers | Organic semiconductor/ferromagnetic bilayer thin films can exhibit novel
properties due to the formation of the spinterface at the interface.
Buckminsterfullerene (C60) has been shown to exhibit ferromagnetism at the
interface when it is placed next to a ferromagnet (FM) such as Fe or Co.
Formation of spinterface occur... | 2102.03914v4 |
2021-05-06 | Interfacial and bulk spin Hall contributions to field-like spin-orbit torque generated by Iridium | We present measurements of spin orbit torques generated by Ir as a function
of film thickness in sputtered Ir/CoFeB and Ir/Co samples. We find that Ir
provides a damping-like component of spin orbit torque with a maximum spin
torque conductivity 1.4e5 in SI unit and a maximum spin-torque efficiency of
0.04, which is su... | 2105.02787v1 |
2021-06-04 | Driving skyrmions with low threshold current density in Pt/CoFeB thin film | Magnetic skyrmions are topologically stable spin swirling particle like
entities which are appealing for next generation spintronic devices. The
expected low critical current density for the motion of skyrmions makes them
potential candidates for future energy efficient electronic devices. Several
heavy metal/ferromagn... | 2106.02407v3 |
2021-08-16 | Highly fcc-textured Pt-Al alloy films grown on MgO(001) showing enhanced spin Hall efficiency | We report on a systematic comparative study of the spin Hall efficiency
between highly face-centered cubic (fcc)-textured Pt-Al alloy films grown on
MgO(001) and poorly-crystallized Pt-Al alloy films grown on SiO$_2$. Using
CoFeB as the detector, we show that for Al compositions centering around $x =
25$, mainly L1$_{2... | 2108.06927v1 |
2021-08-23 | Reconfigurable 3D magnonic crystal: tunable and localized spin-wave excitations in CoFeB meander-shaped film | In this work, we study experimentally by broadband ferromagnetic resonance
measurements, the dependence of the spin-wave excitation spectra on the
magnetic applied field in CoFeB meander-shaped films. Two different
orientations of the external magnetic field were explored, namely parallel or
perpendicular to the lattic... | 2108.10232v1 |
2021-11-16 | Energy-efficient W$_{\text{100-x}}$Ta$_{\text{x}}$/CoFeB/MgO spin Hall nano-oscillators | We investigate a W-Ta alloying route to reduce the auto-oscillation current
densities and the power consumption of nano-constriction based spin Hall nano
oscillators. Using spin-torque ferromagnetic resonance (ST-FMR) measurements on
microbars of W$_{\text{100-x}}$Ta$_{\text{x}}$(5 nm)/CoFeB(t)/MgO stacks with t
= 1.4,... | 2111.08627v1 |
2021-12-23 | Electric-field-induced parametric excitation of exchange magnons in a CoFeB/MgO junction | Electric-field controlled magnetization dynamics is an important integrant in
low power spintronic devices. In this letter, we demonstrate electric-field
induced parametric excitation for CoFeB/MgO junctions by using interfacial
in-plane magnetic anisotropy. When the in-plane magnetic anisotropy and the
external magnet... | 2112.12308v2 |
2022-03-17 | Symmetry effects on the static and dynamic properties of coupled magnetic oscillators | The effect of symmetry on the resonance spectra of antiferromagnetically
coupled oscillators has attracted new interest with the discovery of
symmetry-breaking induced anti-crossings. Here, we experimentally characterise
the resonance spectrum of a synthetic antiferromagnet Pt/CoFeB/Ru/CoFeB/Pt,
where we are able to in... | 2204.01490v1 |
2022-04-25 | Ab-initio study of magneto-ionic mechanisms in ferromagnet/oxide multilayers | The application of gate voltages in heavy metal/ferromagnet/Oxide multilayer
stacks has been identified as one possible candidate to manipulate their
anisotropy at will. However, this method has proven to show a wide variety of
behaviours in terms of reversibility, depending on the nature of the
metal/oxide interface a... | 2204.11699v1 |
2022-06-21 | Extrinsic tunnel Hall effect in CoFeB/MgO/Pt junctions | The Hall effect that occurs when current flows through a CoFeB/MgO/Pt tunnel
junction is investigated. It is shown that the transverse voltage in Pt
electrode is nonlinear on a DC voltage applied to the tunnel junction. It has
both linear (odd) and quadratic (even) parts. The linear part contains
well-known contributio... | 2206.10264v1 |
2023-06-08 | Unidirectionality of spin waves in Synthetic Antiferromagnets | We study the frequency non-reciprocity of the spin waves in symmetric
CoFeB/Ru/CoFeB synthetic antiferromagnets stacks set in the scissors state by
in-plane applied fields. Using a combination of Brillouin Light Scattering and
propagating spin wave spectroscopy experiments, we show that the acoustical
spin waves in syn... | 2306.05259v2 |
2024-03-13 | Theoretical limits of magnetic detection of structural surface defects at the nanometer scale | We present a theoretical study on the magnetic signals of structural surface
defects like cracks or indents combined with rough surfaces or subsurface
inclusions of soft ferromagnetic metals like body-centered cubic Fe or
amorphous CoFeB. We discuss limits of early detection of small surface defects
on the basis of cal... | 2403.08412v1 |
2005-10-18 | Domain imaging, MOKE and magnetoresistance studies of CoFeB films for MRAM applications | We present a detailed study on domain imaging, Kerr effect magnetometry
(MOKE) and magnetoresistance (MR), for a series of 20 nm
Co$_{73.8}$Fe$_{16.2}$B$_{10}$ thin films, both as-deposited (amorphous) and
annealed (crystalline). By considering the two different (orthogonal) in-plane
magnetization components, obtained ... | 0510479v2 |
2014-05-05 | On/off switching of bit readout in bias-enhanced tunnel magneto-Seebeck effect | Thermoelectric effects in magnetic tunnel junctions are currently an
attractive research topic. Here, we demonstrate that the tunnel magneto-Seebeck
effect (TMS) in CoFeB/MgO/CoFeB tunnel junctions can be switched on to a logic
1 state and off to 0 by simply changing the magnetic state of the CoFeB
electrodes. We enabl... | 1405.1064v1 |
2020-05-08 | Nanoscale Spin Injector Driven by a Microwave Voltage | We propose an electrically driven spin injector into normal metals and
semiconductors, which is based on a magnetic tunnel junction (MTJ) subjected to
a microwave voltage. Efficient functioning of such an injector is provided by
electrically induced magnetization precession in the "free" layer of MTJ, which
generates t... | 2005.03896v1 |
2019-12-08 | Thermal Conductivity of Oxide Tunnel Barriers in Magnetic Tunnel Junctions Measured by Ultrafast Thermoreflectance and Magneto-optic Kerr Effect Thermometry | Spin-dependent charge transport in magnetic tunnel junctions (MTJs) can be
manipulated by a temperature gradient, which can be utilized for spintronic and
spin caloritronic applications. Evaluation of the thermally induced phenomena
requires knowledge of the temperature differences across the oxide tunnel
barrier adjac... | 1912.03588v1 |
2021-06-18 | Large perpendicular magnetic anisotropy in Ta/CoFeB/MgO on full coverage monolayer MoS2 and first principle study of its electronic structure | Perpendicularly magnetized spin injector with high Curie temperature is a
prerequisite for developing spin optoelectronic devices on 2D materials working
at room temperature (RT) with zero applied magnetic field. Here, we report the
growth of Ta/CoFeB/MgO structures with a large perpendicular magnetic
anisotropy (PMA) ... | 2106.10317v1 |
2022-10-20 | Ultrafast behavior of induced and intrinsic magnetic moments in CoFeB/Pt bilayers probed by element-specific measurements in the extreme ultraviolet spectral range | The ultrafast and element-specific response of magnetic systems containing
ferromagnetic 3d transition metals and 4d/5d heavy metals is of interest both
from a fundamental as well as an applied research perspective. However, to date
no consensus about the main microscopic processes describing the interplay
between intr... | 2210.11390v3 |
2009-08-17 | The superferromagnetic state in the ensemble of oriented Stoner-Wohlfarth particles: a coercivity due to phase stability | It is observed experimentally that the coercive field has an anomalous
angular dependence at temperatures above the blocking temperature in physically
nonpercolated granular films CoFeB-SiO$_{2}$ with anisotropic granules oriented
in the same direction. It is shown that the anomaly is determined by the
singularity of a... | 0908.2286v1 |
2014-04-04 | Electrical detection of microwave assisted magnetization reversal by spin pumping | Microwave assisted magnetization reversal has been investigated in a bilayer
system of Pt/ferromagnet by detecting a change in the polarity of the spin
pumping signal. The reversal process is studied in two material systems,
Pt/CoFeB and Pt/NiFe, for different aspect ratios. The onset of the switching
behavior is indic... | 1404.1133v1 |
2014-04-04 | Thermally assisted domain wall nucleation in perpendicular anisotropy trilayer nanowires | We study thermally assisted domain wall generation in perpendicular magnetic
anisotropy CoFeB trilayer nanowires by the effect of Joule heating. The
anomalous Hall effect is utilized to detect magnetization reversal in order to
study the domain wall generation. We observe a statistical distribution in the
switching pro... | 1404.1135v1 |
2014-05-14 | Generation of magnonic spin wave traps | Spatially resolved measurements of the magnetization dynamics induced by an
intense laser pump-pulse reveal that the frequencies of resulting spin wave
modes depend strongly on the distance to the pump center. This can be
attributed to a laser generated temperature profile. On a CoFeB thin film
magnonic crystal, Damon-... | 1405.3470v1 |
2017-01-06 | Imaging magnetic vortex configurations in ferromagnetic nanotubes | We image the remnant magnetization configurations of CoFeB and permalloy
nanotubes (NTs) using x-ray magnetic circular dichroism photo-emission electron
microscopy. The images provide direct evidence for flux-closure configurations,
including a global vortex state, in which magnetization points
circumferentially around... | 1701.01685v1 |
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