A5019871847- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Magnetic Properties and Applications
- ZnO doping and properties
- 2D Materials and Applications
- Magneto-Optical Properties and Applications
- Advanced Condensed Matter Physics
- Graphene research and applications
- Topological Materials and Phenomena
- Theoretical and Computational Physics
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Magnetic Properties of Alloys
- Metallurgical and Alloy Processes
- Metallic Glasses and Amorphous Alloys
- Characterization and Applications of Magnetic Nanoparticles
- Semiconductor materials and interfaces
- Surface and Thin Film Phenomena
- Copper Interconnects and Reliability
- Quantum and electron transport phenomena
- Ferroelectric and Negative Capacitance Devices
- Advanced Materials Characterization Techniques
- Intermetallics and Advanced Alloy Properties
- Aluminum Alloys Composites Properties
- Magnetic and transport properties of perovskites and related materials
Indian Institute of Technology Delhi
2018-2024
University of Missouri
2023
Indian Institute of Technology Madras
2023
University of Gothenburg
2023
National Institute of Science Education and Research
2012-2020
Institute of Physics, Bhubaneshwar
2014
The generation of out-of-plane polarized spin current is crucial for efficiently manipulating perpendicularly magnetized systems used in high-density magnetic recording. Here, we demonstrate the at room temperature using an insulator, EuS. By employing angle-resolved spin-torque ferromagnetic resonance, find a large unconventional torque conductivity,...
Spin-to-charge conversion is an essential requirement for the implementation of spintronic devices. Recently, monolayers (MLs) semiconducting transition-metal dichalcogenides (TMDs) have attracted considerable interest spin-to-charge due to their high spin-orbit coupling and lack inversion symmetry in crystal structure. However, reports direct measurement at TMD-based interfaces are very much limited. Here, we report on room-temperature observation a large arising from interface Ni80Fe20...
Effect of substrate rotation on anisotropy and domain structure for a thin ferromagnetic film has been investigated in this work. For purpose Co films with 10 nm thickness have prepared by sputtering oblique angle incidence various rotations. This method preparation induces uniaxial due to shadow deposition effect. The magnetization reversal is studied magneto-optic Kerr effect (MOKE) based microscope the longitudinal geometry. rotating 20 rpm weakens but does not completely give isotropic...
Angle-resolved spin-torque ferromagnetic resonance measurements are carried out in heterostructures consisting of Py (Ni$_{81}$Fe$_{19}$) and a noncollinear antiferromagnetic quantum material $\gamma-$IrMn$_{3}$. The structural characterization reveals that $\gamma-$IrMn$_{3}$ is polycrystalline nature. A large exchange bias 158~Oe found Py/$\gamma-$IrMn$_{3}$ at room temperature, while $\gamma-$IrMn$_{3}$/Py Py/Cu/$\gamma-$IrMn$_{3}$ exhibited no bias. Regardless the stacking sequence, we...
Epitaxial Fe thin films were grown on annealed MgO(001) substrates at oblique incidence by DC magnetron sputtering. Due to the growth configuration, uniaxial anisotropy was found be superimposed expected four-fold cubic anisotropy. A detailed study of in-plane magnetic hysteresis for MgO has been performed Magneto Optic Kerr Effect (MOKE) magnetometer. Both single step and double loops have observed depending angle between applied field easy axis i.e. along ⟨100⟩ direction. Domain images...
We report on ferromagnetic resonance spectroscopy studies of Py/Gd system by varying thickness Gd layer. found that a portion the layer at interface becomes ferromagnetically ordered room temperature and become antiferromagnetic coupled to Py due magnetic proximity effect, as evidenced Gd-thickness dependent shift in field exchange bias field. show large increase effective Gilbert damping when adjacent is increased. argue major contribution this spin pumping effect into
Fe3Sn2, a kagome ferromagnet, is potential quantum material with intriguing topological features. Despite substantial experimental work on the bulk single crystals, thin film growth of Fe3Sn2 remains relatively unexplored. Here, we investigate effect two different seed layers (Ta and Pt) films. We demonstrate polycrystalline films Si/SiO2 substrates by room temperature sputter deposition, followed in situ annealing at 500 °C. Our structural magnetic measurements indicate that pure...
We report on a direct measurement of sizable interfacial Dzyaloshinskii-Moriya interaction (iDMI) at the interface two-dimensional transition metal dichalcogenide (2D-TMD), MoS$_{\rm 2}$ and Ni$_{80}$Fe$_{20}$ (Py) using Brillouin light scattering spectroscopy. A clear asymmetry in spin-wave dispersion is measured 2}$/Py/Ta, while no such detected reference Py/Ta system. linear scaling DMI constant with inverse Py thickness indicates origin observed DMI. further observe an enhancement three...
Ultrafast generation of spin currents involving antiferromagnets is currently attracting tremendous interest. Here, we demonstrate broadband THz emission from a [111]-oriented NiO/Pt bilayer grown on MgO and Al2O3 substrates. The NiO films are by pulsed laser deposition, whereas the Pt magnetron sputtering. While obtained epitaxial both substrates, substrate showed presence crystalline twins. We show that existence twins reduces amplitude an order magnitude while simultaneously dramatically...
As a topological Dirac semimetal with controllable spin–orbit coupling and conductivity, PtSe2, transition-metal dichalcogenide, is promising material for several applications, from optoelectrics to sensors. However, its potential spintronics applications has yet be explored. In this work, we demonstrate that the PtSe2/Ni80Fe20 heterostructure can generate large damping-like current-induced torques (SOT), despite absence of spin-splitting in bulk PtSe2. The efficiency charge-to-spin...
Abstract Mn 3 Sn is a non‐collinear antiferromagnetic quantum material that exhibits magnetic Weyl semimetallic state and has great potential for efficient memory devices. High‐quality epitaxial c ‐plane thin films have been grown on sapphire substrate using Ru seed layer. Using spin pumping induced inverse Hall effect measurements Sn/Ni 80 Fe 20 , spin‐diffusion length (), conductivity (σ SH ) of are measured: nm cm −1 . While consistent with earlier studies, σ an order magnitude higher the...
Co thin films on Si (1 0 0) substrates with different seed layers (Au or AlOX) have been deposited for variable speed of substrate rotation (Rsub) at room temperature (RT) 200 °C. Hysteresis measurements by magneto optic Kerr effect reveals that the show growth induced uniaxial anisotropy when prepared without (i.e. Rsub = rpm). The RT a decrease but non-vanishing increase in Rsub. However, high deposition along leads to formation isotropic films. change has quantitatively investigated using...
X-ray photoemission electron microscopy (XPEEM) and magneto-optic Kerr effect (MOKE) have been performed on a metal-insulator multilayer of $[{\mathrm{Co}}_{80}{\mathrm{Fe}}_{20}(t=1.8\phantom{\rule{4pt}{0ex}}\mathrm{nm}$)/${\mathrm{Al}}_{2}{\mathrm{O}}_{3}{(3\phantom{\rule{4pt}{0ex}}\mathrm{nm})]}_{9}$ to image ${360}^{\ensuremath{\circ}}$ domain walls (DWs) along easy hard axes, respectively. Their creation annihilation can be directly visualized under application magnetic field. XPEEM...
The magnetization reversal process has been studied on a discontinuous metal-insulator multilayer sample [Co80Fe20(1.3 nm)/Al2O3(3 nm)]10 showing superferromagnetic (SFM) behavior. Size and shape of SFM domains can be changed by varying the angle θ between magnetic field easy axis (EA). along EA is governed domain wall motion. However, upon approaching hard at increasing coherent rotation superspins becomes dominant in process. This leads to reduction sizes for larger values θ. relaxation...
We perform a comparative study of spin pumping in NiO/Ni[Formula: see text]Fe[Formula: text] (Py) by altering the crystallinity NiO. simultaneously grow high-quality NiO/Py heterostructures on Si/SiO 2 and Al O 3 (0001) substrates. Although growth substrate produced polycrystalline NiO (Poly-NiO), epitaxial (Epi-NiO). Our ferromagnetic resonance measurements reveal presence two-magnon scattering (TMS) measured linewidth for Epi-NiO/Py system. By carefully considering contribution TMS, we...
In a dense ensemble of magnetic nanoparticles, but still below physical percolation, sufficiently strong interactions can be experienced to form superferromagnetic (SFM) state. SFM domains in non-percolated nanoparticle assembly are expected similar conventional FM continuous film, with the decisive difference that atomic spins replaced by superspins single-domain nanoparticles. this article, Kerr microscopy has been performed on granular multilayer [Co80Fe20(1.3nm)/Al2O3(3nm)]10 study...
Understanding and tailoring of anisotropy in magnetic thin films has been interesting due to its application data storage devices magnetoresitive devices. Anisotropy can be induced a film by oblique deposition, applying field during post annealing (annealing presence or annealing) etc. During deposition shadow effect columnar structures grains grow with tilt towards the angle. However some applications e.g. microwave fundamental studies it is desirable overcome anisotropy. One method rotate...
Mn$_3$Sn is a non-collinear antiferromagnetic quantum material that exhibits magnetic Weyl semimetallic state and has great potential for efficient memory devices. High-quality epitaxial $c$-plane thin films have been grown on sapphire substrate using Ru seed layer. Using spin pumping induced inverse Hall effect measurements Mn$_3$Sn/Ni$_{80}$Fe$_{20}$, we measure spin-diffusion length ($\lambda_{\rm Mn_3Sn}$), conductivity ($\sigma_{\rm{SH}}$) of films: $\lambda_{\rm Mn_3Sn}=0.42\pm 0.04$...