We have studied surface morphology and magnetic properties of Fe/MgO(001) films deposited at an angle varying between 0o and 60o with respect to the surface normal and with azimuth along the Fe[010] or the Fe[110] direction. Due to shadowing, elongated grains appear on the film surface for deposition at sufficiently large angle. X-ray reflectivity reveals that, depending on the azimuthal direction, films become either rougher or smoother for oblique deposition. For deposition along Fe[010] the pronounced uniaxial magnetic anisotropy (UMA) results in the occurrence of reversed two-step and of three-step hysteresis loops. For deposition along Fe[110] the growth-induced UMA is much weaker, causing a small rotation of the easy axes.
Atomic scale computer simulations on structures and photo induced volume changes of flatly and obliquely deposited amorphous selenium films have been carried out in order to understand how the properties of chalcogenide glasses are influenced by their preparation method. Obliquely deposited a-Se thin films contain more coordination defects, larger voids than the flatly deposited ones. To model the photo induced volume changes the electron excitation and hole creation were treated independently within the framework of tight-binding formalism. Covalent and interchain bond breakings and formation…
The ability to tailor the damping factor is essential for spintronic and spin-torque applications. Here, we report an approach to manipulate the damping factor of FeGa/MgO(001) films by oblique deposition. Owing to the defects at the surface or interface in thin films, two-magnon scattering (TMS) acts as a non-Gilbert damping mechanism in magnetization relaxation. In this work, the contribution of TMS was characterized by in-plane angular dependent ferromagnetic resonance (FMR). It is demonstrated that the intrinsic Gilbert damping is isotropic and invariant, while the extrinsic mechanism rela…
Improving reactivity on an insulating surface is crucial due to their important applications in surface catalytic reactions. In this work, we carried out first-principles calculations to investigate the adsorption of O2 on a single-layer MgO(100) film deposited on metal substrate. The adsorption configurations, reaction pathways, molecular dynamics simulations, and electronic properties are reported. We reveal that O2 can completely dissociate on the surface, which is in sharp contrast to that on MgO(100) films thicker than one monolayer. The dissociated O2 tends to penetrate into the interfac…
Most commercial high-temperature superconducting coated conductors based on ion beam assisted MgO deposited templates use $\mathrm{LaMnO_3}$ (LMO) films as the terminating buffer layer. In contrast, coated conductors based on inclined substrate deposition (ISD)-MgO technology are still produced with homoepitaxial (homoepi)-MgO as the cap layer. In this work we report on the deposition of LMO buffer layers on ISD-MgO/homoepi-MgO by electron beam physical vapor deposition. The growth parameters of textured LMO films were studied systematically and their properties were optimized regarding the cr…
The influence of a patterned substrate on obliquely deposited, exchange biased Co/CoO films was studied. It was found that substrates decorated with nanoparticle patterns provide the option to manipulate the orientation of the magnetic easy axis in obliquely deposited thin films. The complementary methods of SQUID magnetometry and polarized neutron reflectometry were used to disentangle the different contributions to the magnetic hysteresis of such complex magnetic systems.
We investigated the dependence of giant tunnel magnetoresistance (TMR) on the thickness of an MgO barrier and on the annealing temperature of sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions deposited on SiO2/Si wafers. The resistance-area product exponentially increases with MgO thickness, indicating that the quality of MgO barriers is high in the investigated thickness range of 1.15-2.4 nm. High-resolution transmission electron microscope images show that annealing at 375 C results in the formation of crystalline CoFeB/MgO/CoFeB structures, even though CoFeB electrodes are amorphous in th…
Present work investigates the magnetic and electronic structure of MgO/Fe/MgO/Fe/Co/Au multilayer stack grown on Si(100) substrates by electron beam evaporation method. X-ray diffraction study depicts polycrystalline nature of the multilayers. Results obtained from vibrating sample magnetometry (VSM) and near-edge X-ray absorption fine structure spectra (NEXAFS) at Fe & Co L- and Mg & O K-edges are applied to understand the magnetic and electronic properties of this stack and its interface properties. While the spectral features of Fe L-edge spectrum recorded by surface sensitive total electro…
Oblique angle deposited oxide thin films have opened up new dimensions in fabricating optical interference devices with tailored refractive index profile along thickness by tuning its microstructure by varying angle of deposition. Microstructure of thin films strongly affects surface morphology as well as optical properties. Since surface morphology plays an important role for the qualification of thin film devices for optical or other applications, it is important to investigate morphological properties. In present work, HfO2 thin films have been deposited at several oblique angles. Morpholog…
The atomic interaction and magnetic properties of ultrathin Fe films grown on cleaved and polished MgO(100) surfaces were studied by conversion electron Mössbauer spectroscopy (CEMS) in broad temperature range. Fe with different layer thickness was deposited on MgO substrates. The layers were formed on polished and cleaved substrate surfaces at RT. The analysis of the spectra showed no Fe-O$^{2-}$ interaction in MgO/Fe interface. Iron layers showed different magnetic anisotropy depending on their thickness.
Oblique angle deposition of oxides is being famous for fabricating inhomogeneous thin films with variation of refractive index along thickness in a functional form. Inhomogeneous layers play a key role in the development of rugate interference devices for photo-physical applications. Such obliquely deposited thin films show high porosity which is a critical issue related to their mechanical and environmental stability. Hence, it is important to investigate elastic properties of such film in addition to optical properties. Using atomic force acoustic microscopy, we report indentation modulus of…
Many technologies require highly-oriented and textured functional thin films. The most common synthe-sis approaches use on-axis sputter geometries. However, in some scenarios, on-axis sputtering is not feasible. During ionized physical vapor deposition (PVD), in contrast to conventional PVD, the film-forming species can be accelerated onto the growing film using substrate-bias potentials. This increas-es the ad-atom mobility, but also deflects the trajectory of ions towards the substrate increasing the texture of the growing film. However, potential gas-ion incorporation in the films limits th…
Low-energy deposition of neutral Pd_N clusters (N=2-7 and 13) on a MgO(001) surface F-center (FC) was studied by spin-density-functional molecular dynamics simulations. The incident clusters are steered by an attractive "funnel" created by the FC, resulting in adsorption of the cluster, with one of its atoms bonded atop of the FC. The deposited Pd_2-Pd_6 clusters retain their gas-phase structures, while for N>6 surface-commensurate isomers are energetically more favorable. Adsorbed clusters with N > 3 are found to remain magnetic at the surface.
We investigated dependence of tunnel magnetoresistance effect in CoFeB/MgO/CoFeB magnetic tunnel junctions on Ar pressure during MgO-barrier sputtering. Sputter deposition of MgO-barrier at high Ar pressure of 10 mTorr resulted in smooth surface and highly (001) oriented MgO. Using this MgO as a tunnel barrier, tunnel magnetoresistance (TMR) ratio as high as 355% at room temperature (578% at 5K) was realized after annealing at 325 C or higher, which appears to be related to a highly (001) oriented CoFeB texture promoted by the smooth and highly oriented MgO. Electron-beam lithography defined d…
Uniaxial Magnetic Anisotropy and Type-X/Y Current-Induced Magnetization Switching in Oblique-Angle-Deposited Ta/CoFeB/Pt and W/CoFeB/Pt Heterostructures
We report the successful fabrication of superconducting tantalum nitride (TaN) thin films using a pulsed laser deposition technique with 1064 nm radiation. Films with thickness $ \sim $ 100 nm deposited on MgO (100) single crystals and on oxidized silicon (SiO$_{2} $) substrates exhibited a superconducting transition temperature of $\sim $ 8 K and 6 K, respectively. The topography of these films were investigated using atomic force and scanning electron microscopy, revealing fairly large area particulate free and smooth surfaces, while the structure of the films were investigated using standar…
We investigate thickness series of films of the Heusler alloy Co$_2$FeAl in order to study the effect of annealing on the interface with a MgO layer and on the bulk magnetic properties. Our results reveal that while the perpendicular interface anisotropy constant $K^{\perp}_{\rm S}$ is zero for the as-deposited samples, its value increases with annealing up to a value of $1.14\, \pm \,0.07$~mJ/m$^2$ for the series annealed at 320$^{\rm o}$C and of $2.07\, \pm \,0.7$~mJ/m$^2$ for the 450$^{\rm o}$C annealed series owing to a strong modification of the interface during the thermal treatment. Thi…
The preparation of Ag 2+x Se thin films with thicknesses between 4 nm and 3000 nm by pulsed laser deposition on single crystalline NaCl and MgO substrates is reported. The films are perfectly dense and show a good lateral uniformity with a small number of defects. The microstructure of the films corresponds to a nanoparquet, being composed of two different phases of silver selenide. One phase is identified as the Naumannite low temperature phase of silver selenide, the structure of the other phase has not been reported in detail before and probably represents a metastable phase. Silver-rich fi…
We investigated the temperature dependence of the switching current for a perpendicularly magnetized CoFeB film deposited on a nanocrystalline tungsten film with large oxygen content: nc-W(O). The spin Hall angle $|Θ_\mathrm{SH}| \approx 0.22$ is independent of temperature, whereas the switching current increases strongly at low temperature. We show that the nc-W(O) is insensitive to annealing. It thus can be a good choice for the integration of spin Hall driven writing of information in magnetic memory or logic devices that require a high-temperature annealing process during fabrication.
Biaxially textured LuNi2BC thin films with Tc up to 15.8 K and a residual resistivity ratio up to 15 have been prepared. The films were deposited on MgO(110) substrates using pulsed laser deposition from a stoichiometric target. Via the precise control of the deposition rate, a biaxial texture is favored within a broad range of the deposition temperature. The full epitaxial relationship between the borocarbide film, the \luo interface layer and the substrate is (110)[001]MgO II (110)[001]Lu2O3 II (001)[100]LuNi2B2C. A very sharp in--plane alignment of about 1\textdegree and an out--of--plane o…
Thin films of the proposed topological insulator PdLuBi - a Heusler compound with the C1b structure - were prepared on Ta-Mo-buffered MgO(100) substrates by co-sputtering from PdBi2 and Lu targets. Epitaxial growth of high-quality PdLuBi films was confirmed by X-ray spectrometry and reflection high-energy electron diffraction. The root-mean-square roughness of the films was as low as 1.45 nm, although the films were deposited at high temperature. The film composition is close to the ideal stoichiometric ratio. The valence band spectra of the PdLuBi films, observed by hard X-ray photoelectron s…
Recently, it has been shown that magnetic tunnel junctions with thin MgO tunnel barriers exhibit extraordinarily high tunneling magnetoresistance (TMR) values at room temperature1, 2. However, the physics of spin dependent tunneling through MgO barriers is only beginning to be unravelled. Using planar magnetic tunnel junctions in which ultra-thin layers of magnetic metals are deposited in the middle of a MgO tunnel barrier here we demonstrate that the TMR is strongly modified when these layers are discontinuous and composed of small pancake shaped nanodots. At low temperatures, in the Coulomb …
We have investigated the influence of the superconducting layer thickness, d, on the structural and transport properties of Co-doped BaFe2As2 films deposited on Fe-buffered MgO substrates by pulsed laser deposition. The superconducting transition temperature and the texture quality of Co-doped BaFe2As2 films improve with increasing d due to a gradual relief of the tensile strain. For d>90 nm an additional 110 textured component of Co-doped BaFe2As2 was observed, which leads to an upward shift in the angular dependent critical current density at H // c. These results indicate that the grain bou…
We investigate the growth of thin Fe layers on MgAl$_2$O$_4$~(001) and MgO~(001) substrates using dc magnetron sputtering. The crystal quality of Fe layers deposited on MgAl$_2$O$_4$ is found to be substantially higher as compared to Fe grown on MgO substrates. The effects of the crystal quality on the magnetic and electronic transport properties are discussed.
10 nm and 50 nm Co$_{2}$FeAl (CFA) thin films have been deposited on MgO(001) and Si(001) substrates by magnetron sputtering and annealed at different temperatures. X-rays diffraction revealed polycrystalline or epitaxial growth (according to the relation CFA(001)[110]//MgO(001)[100] epitaxial relation), respectively for CFA films grown on a Si and on a MgO substrate. For these later, the chemical order varies from the A2 phase to the B2 phase when increasing the annealing temperature (Ta) while only the A2 disorder type has been observed for CFA grown on Si. Microstrip ferromagnetic resonance…
We investigated structural, magnetic and electrical properties of sputter deposited Mn-Fe-Ga compounds. The crystallinity of the Mn-Fe-Ga thin films was confirmed using x-ray diffraction. X-ray reflection and atomic force microscopy measurements were utilized to investigate the surface properties, roughness, thickness and density of the deposited Mn-Fe-Ga. Depending on the stoichiometry, as well as the used substrates (SrTiO3 (001) and MgO (001)) or buffer layer (TiN) the Mn-Fe-Ga crystallizes in the cubic or the tetragonally distorted phase. Anomalous Hall effect and alternating gradient magn…
In this paper, we have studied the effect of strain relaxation on magneto-transport properties of La_0.7Ca_0.3MnO_3 epitaxial films (200 nm thick), which were deposited by pulsed laser deposition technique under identical conditions. All the films are epitaxial and have cubic unit cell. The amount of strain relaxation has been varied by taking three different single crystal substrates of SrTiO_3, LaAlO_3 and MgO. It has been found that for thicker films the strain gets relaxed and produces variable amount of disorder depending on the strength of strain relaxation. The magnitude of lattice rela…
Magnetic heterostructure Mo/CoFeB/MgO has strong perpendicular magnetic anisotropy and thermal stability. Through current-induced hysteresis loop shift measurements, we show that the dampinglike spin-orbit torque (SOT) efficiency of Mo/CoFeB/MgO heterostructure is $ξ_{DL}\approx -0.003\pm 0.001$ and fairly independent of the annealing temperature from 300$^\circ$C to 400$^\circ$C. Though $|ξ_{DL}|$ is small while compare to those from Ta or W-based heterostructures, reversible current-induced SOT switching of a thermally-stable Mo/CoFeB/MgO heterostruture can still be achieved. Furthermore, we…
We have studied electric-field-induced symmetry lowering in the tetragonal (001)-oriented heteroepitaxial (Ba$_{0.8}$Sr$_{0.2}$)TiO$_3$ thin film deposited on (001)MgO substrate. Polarized micro-Raman spectra were recorded from the film area in between two planar electrodes deposited on the film surface. Presence of \textit{c}-domains with polarization normal to the substrate was confirmed from polarized Raman study under zero field, while splitting and hardening of the \textit{E}(TO) soft mode and polarization changes in the Raman spectra suggest monoclinic symmetry under external electric fi…
We grow epitaxial Sm-Co thin films by sputter deposition from an alloy target with a nominal SmCo5 composition on Cr(100)-buffered MgO(100) single-crystal substrates. By varying the Ar gas pressure, we can change the composition of the film from a SmCo5-like to a Sm2Co7-like phase. The composition, crystal structure, morphology and magnetic properties of these films have been determined using Rutherford Backscattering, X-ray diffraction and magnetization measurements. We find that the various properties are sensitive to the sputter background pressure in different ways. In particular, the latt…
Co2FeAl (CFA) thin films with thickness varying from 10 nm to 115 nm have been deposited on MgO(001) substrates by magnetron sputtering and then capped by Ta or Cr layer. X-rays diffraction (XRD) revealed that the cubic $[001]$ CFA axis is normal to the substrate and that all the CFA films exhibit full epitaxial growth. The chemical order varies from the $B2$ phase to the $A2$ phase when decreasing the thickness. Magneto-optical Kerr effect (MOKE) and vibrating sample magnetometer measurements show that, depending on the field orientation, one or two-step switchings occur. Moreover, the films …
The effects of substrate treatment, temperature and composition on the surface morphology of Ni-Cr thin films grown on MgO(001) are studied by scanning tunneling microscopy (STM) and atomic force microscopy (AFM). A combination of acid-etching and high temperature deposition (400C) will result in smooth films and terraces (up to 30 nm wide) suitable for the study of progression of chemical reactions on the surface. Two different treatments are used to prepare the MgO substrates for deposition and they introduce characteristic differences in film surface morphology. Thin films that are grown on…
Oblique/normal sequential deposition technique is used to create Co based unique multilayer structure [Co-oblique(4.4nm)/Co-normal (4.2 nm)]x10, where each Co-oblique layer is deposited at an oblique angle of 75deg, to induce large in-plane uniaxial magnetic anisotropy (UMA). Compared to the previous ripple, stress and oblique angle deposition (OAD) related studies on Cobalt in literature, one-order higher UMA with the easy axis of magnetization along the projection of the tilted nano-columns in the multilayer plane is observed. The multilayer retains magnetic anisotropy even after annealing a…
In this study, to obtain perpendicular magnetic tunnel junctions (p-MTJs) using half-metallic ferromagnets (HMFs), several methods were developed to induce perpendicular magnetic anisotropy (PMA) in full-Heusler Co2FeSi (CFS) alloy thin layers in an MTJ multilayer composed of a layered CFS/MgO/CFS structure. Oxygen exposure at 2.0 Pa for 10 min after deposition of the bottom CFS layer was effective for obtaining PMA in the CFS layer. One of the reasons for the PMA is the formation of nearly ideal CFS/MgO interfaces due to oxygen exposure before the deposition of the MgO layer. The annealing pr…
The ferrimagnetic Heusler compound Mn2VGa is predicted to have a pseudogap in the majority spin channel, which should lead to a negative tunnel magnetoresistance. We synthesized epitaxial Mn2VGa thin films on MgO(001) substrates by dc and rf magnetron co-sputtering, resulting in nearly stoichiometric films. XRD analysis revealed a mostly B2-ordered structure for the films deposited at substrate temperatures of 350°C, 450°C, and 550°C. Magnetic tunnel junctions with MgO barrier and CoFe counter-electrodes were fabricated. After post-annealing at up to T_a=425°C negative TMR was obtained around …
The magnetization of thin films of cobalt ferrite frequently falls far below the bulk value of 455 kAm-1, which corresponds to an inverse cation distribution in the spinel structure with a significant orbital moment of about 0.6 muB that is associated with the octahedrally-coordinated Co2+ ions. The orbital moment is responsible for the magnetostriction and magnetocrystalline anisotropy, and its sensitivity to imposed strain. We have systematically investigated the structure and magnetism of films produced by pulsed-laser deposition on different substrates (TiO2, MgO, MgAl2O4, SrTiO3, LSAT, La…
We investigate the effect of atomic ordering on the magnetic anisotropy of Ni80Fe20 at.% (Py). To this end, Py films were grown epitaxially on MgO (001) using dc magnetron sputtering (dcMS) and high power impulse magnetron sputtering (HiPIMS). Aside from twin boundaries observed in the latter case, both methods present high quality single crystals with cube-on-cube epitaxial relationship as verified by the polar mapping of important crystal planes. However, X-ray diffraction results indicate higher order for the dcMS deposited film towards L12 Ni3Fe superlattice. This difference can be underst…
HRTEM, nano-beam electronic diffraction, energy dispersive X-rays scanning spectroscopy, Vibrating Sample Magnetometry (VSM) and FerroMagnetic Resonance (FMR) techniques are used in view of comparing (static and dynamic) magnetic and structural properties of Co2MnGe (13 nm)/Al2O3 (3 nm)/Co (13 nm) tunnel magnetic junctions (TMJ), deposited on various single crystalline substrates (a-plane sapphire, MgO(100) and Si(111)). They allow for providing a correlation between these magnetic properties and the fine structure investigated at atomic scale. The Al2O3 tunnel barrier is always amorphous and …
Here we systematically explore the use of pulsed laser deposition technique (PLD) to grow three basic oxides that have rocksalt structure but different chemical stability in the ambient atmosphere: NiO (stable), MnO (metastable) and EuO (unstable). By tuning laser fluence, an epitaxial single-phase nickel oxide thin-film growth can be achieved in a wide range of temperatures from 10 to 750 °C. At the lowest growth temperature, the out-of-plane strain raises to 1.5%, which is five times bigger than that in a NiO film grown at 750 °C. MnO thin films that had long-range ordered were successfully …
L10-FePt distinguishes itself for its ultrahigh perpendicular magnetic anisotropy (PMA), which enables memory cells with sufficient thermal stability to scale down to 3 nm. The recently discovered "bulk" spin-orbit torques in L10-FePt provide an efficient and scalable way to manipulate the L10-FePt magnetization. However, the existence of external field during the switching limits its practical application, and therefore field-free switching of the L10-FePt is in highly demand. In this manuscript, we demonstrate the field-free switching of the L10-FePt by growing it on vicinal MgO (001) substr…
We deposited epitaxial thin films of Morphotropic Phase Boundary (MPB) Pb0.65Ba0.35Nb2O6 (PBN:65) on MgO substrates using pulsed laser deposition. Afterwards, a novel transmission optical experiment was developed to measure the electric field-induced bending angle of the thin film sample using a divergent incident light. From which the electric field-induced strain was obtained, and it was used to calculate the electrostrictive constant of the PBN thin film. The result is 0.000875 um2/V2, and it is consistent with what we measured in the reflection experiment.
Interfacial mixing of elements is a well-known phenomenon found in thin film deposition. For thin-film magnetic heterostructures, interfacial compositional inhomogeneities can have drastic effects on the resulting functionalities. As such, care must be taken to characterize the compositional and magnetic properties of thin films intended for device use. Recently, ferrimagnetic Mn$_4$N thin films have drawn considerable interest due to exhibiting perpendicular magnetic anisotropy, high domain-wall mobility, and good thermal stability. In this study, we employed X-ray photoelectron spectroscopy …
The selection rule for angle-resolved polarized Raman (ARPR) intensity of phonons from standard group-theoretical method in isotropic materials would break down in anisotropic layered materials (ALMs) due to birefringence and linear dichroism effects. The two effects result in depth-dependent polarization and intensity of incident laser and scattered signal inside ALMs and thus make a challenge to predict ARPR intensity at any laser incidence direction. Herein, taking in-plane anisotropic black phosphorus as a prototype, we developed a so-called birefringence-linear-dichroism (BLD) model to qu…
Co$_2$FeSi(100) films with L2$_1$ structure deposited onto MgO(100) were studied exploiting both longitudinal (LMOKE) and quadratic (QMOKE) magneto-optical Kerr effect. The films exhibit a huge QMOKE signal with a maximum contribution of up to 30 mdeg, which is the largest QMOKE signal in reflection that has been measured thus far. This large value is a fingerprint of an exceptionally large spin-orbit coupling of second or higher order. The Co$_2$FeSi(100) films exhibit a rather large coercivity of 350 and 70 Oe for film thicknesses of 22 and 98 nm, respectively. Despite the fact that the film…
We report structural, optical, temperature and frequency dependent dielectric, and energy storage properties of pulsed laser deposited (100) highly textured BaZr(x)Ti(1-x)O3 (x = 0.3, 0.4 and 0.5) relaxor ferroelectric thin films on La0.7Sr0.3MnO3/MgO substrates which make this compound as a potential lead-free capacitive energy storage material for scalable electronic devices. A high dielectric constant of ~1400 - 3500 and a low dielectric loss of <0.025 were achieved at 10 kHz for all three compositions at ambient conditions. Ultrahigh stored and recoverable electrostatic energy densities as…
In their rocksalt structure, rare-earth monosulfides offer a more stable alternative to alkali metals to attain low or negative electron affinity when deposited on various III-V and II-VI semiconductor surfaces. In this article, we first describe the successful deposition of Lanthanum Monosulfide via pulsed laser deposition on Si and MgO substrates and alumina templates. These thin films have been characterized by X-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy, ellipsometry, Raman spectroscopy, ultraviolet photoelectron spectroscopy and Kelvin prob…
We present a thorough research on Ta/Ru-based buffers and their influence on features crucial from the point of view of applications of MTJs, such as critical switching current and thermal stability. We investigate devices consisting of buffer/FeCoB/MgO/FeCoB/Ta/Ru multilayers for three different buffers: Ta 5 / Ru 10 / Ta 3, Ta 5 / Ru 10 / Ta 10 and Ta 5 / Ru 20 / Ta 5 (all thicknesses in nm). In addition, we study systems with a single FeCoB layer deposited above as well as below the MgO barrier. The crystallographic texture and the roughness of the buffers are determined by means of XRD and…
Spin-gapless semiconductors with their unique band structures have recently attracted much attention due to their interesting transport properties that can be utilized in spintronics applications. We have successfully deposited the thin films of quaternary spin-gapless semiconductor CoFeMnSi Heusler alloy on MgO (001) substrates using a pulsed laser deposition system. These films show epitaxial growth along (001) direction and display uniform and smooth crystalline surface. The magnetic properties reveal that the film is ferromagnetically soft along the in-plane direction and its Curie tempera…
Tilted off-plane magnetic anisotropy induces two unusual characteristic magnetotransport phenomena: extraordinary Hall effect in the presence of an in-plane magnetic field, and non-monotonic anisotropic magnetoresistance in the presence of a field normal to the sample plane. We show experimentally that these effects are generic, appearing in multiple ferromagnetic systems with tilted anisotropy introduced either by oblique deposition from a single source or in binary systems co-deposited from separate sources. We present a theoretical model demonstrating that these observations are natural res…
We study static and dynamic magnetic properties of Co2MnGe (13 nm)/Al2O3 (3 nm)/Co (13 nm) tunnel magnetic junctions (TMJ), deposited on various single crystalline substrates (a-plane sapphire, MgO(100), Si(111)). The results are compared to the magnetic properties of Co and of Co$_{2}$MnGe single films lying on sapphire substrates. X-rays diffraction always shows a (110) orientation of the Co$_{2}$MnGe films. Structural observations obtained by high resolution transmission electron microscopy confirmed the high quality of the TMJ grown on sapphire. Our vibrating sample magnetometry measuremen…
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 measurements in a Co2MnGa/Ti/CoFeB heterostructure and a relatively large spin Hall efficiency of -7.8% was obtained.The SOT-induced magnetization switching of the perpendicularly magnetized CoFeB layer was further demonstrated using the structure. The symmetry of second harmonic signals, t…
Cubic spinel CoCr2O4 has attained recent attention due to its multiferroic properties. However, the Co site substitution effect on the structural and magnetic properties has rarely been studied in thin film form. In this work, the structural and magnetic properties of Co1-xNixCr2O4 (x = 0, 0.5) epitaxial thin films deposited on MgAl2O4 (100) and MgO (100) substrates to manipulate the nature of strain in the films using pulsed laser deposition (PLD) technique are presented. The epitaxial nature of the films was confirmed through X-ray diffraction (XRD) and Rutherford backscattering spectrometry…
In this study we report on the film growth and characterization of thin (approximately 50 nm thick) Ti-Fe-C films deposited on amorphous quartz. The experimental studies have been complemented by first principles density functional theory (DFT) calculations. Upon annealing of as-prepared films, the composition of the metastable Ti-Fe-C film changes. An iron-rich phase is first formed close to the film surface, but with increasing annealing time this phase is gradually displaced toward the film-substrate interface where its position stabilizes. Both the magnetic ordering temperature and the sat…
The structural, magnetic, and magnetocaloric properties of epitaxial Ni-Co-Mn-Al thin films with different compositions have been studied. The films were deposited on MgO(001) substrates by co-sputtering on heated substrates. All films show a martensitic transformation, where the transformation temperatures are strongly dependent on the composition. The structure of the martensite phase is shown to be 14M. The metamagnetic martensitic transformation occurs from strongly ferromagnetic austenite to weakly magnetic martensite. The structural properties of the films were investigated by atomic for…
