A5005368428- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Multiferroics and related materials
- Iron oxide chemistry and applications
- Heusler alloys: electronic and magnetic properties
- Characterization and Applications of Magnetic Nanoparticles
- Magneto-Optical Properties and Applications
- Magnetic Properties and Synthesis of Ferrites
- Advanced Thermoelectric Materials and Devices
- 2D Materials and Applications
- Graphene research and applications
- Nanoparticle-Based Drug Delivery
- ZnO doping and properties
- Magnetic Properties and Applications
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Shape Memory Alloy Transformations
- Magnetism in coordination complexes
- Thermal Expansion and Ionic Conductivity
- Electromagnetic wave absorption materials
- Magnetic Field Sensors Techniques
- Advanced NMR Techniques and Applications
- Photonic Crystals and Applications
- Catalysis and Oxidation Reactions
University of South Florida
2021-2025
Technical University of Denmark
2024-2025
Uppsala University
2022
Phenikaa University
2022
National University of Singapore
2017-2021
Republic Polytechnic
2019
Nanyang Technological University
2017
Iron oxide (e.g., Fe3O4 or γ-Fe2O3) nanoparticles are promising candidates for a variety of biomedical applications ranging from magnetic hyperthermia therapy to drug delivery and biodetection due their superparamagnetism, nontoxicity, biodegradability. While particles small size (below critical size, ∼20 nm) display superparamagnetic behavior at room temperature, these tend penetrate highly sensitive areas the body such as blood–brain barrier, leading undesired effects. In addition, possess...
Valence tautomerism in conductive lanthanide–organic frameworks is robust and tunable via alloying. Trivalent metal ions raise the conversion temperature without losing cooperativity, while divalent lower it weaken cooperativity.
The magnon propagation length, ⟨ξ⟩, of a ferro-/ferrimagnet (FM) is one the key factors that controls generation and thermally driven magnonic spin current in FM/heavy metal (HM) bilayer based spincaloritronic devices. For development complete physical picture transport FM/HM bilayers over wide temperature range, it utmost importance to understand respective roles temperature-dependent Gilbert damping (α) effective magnetic anisotropy (Keff) controlling evolution ⟨ξ⟩. Here, we report...
Abstract The authors report on a systematic investigation of the longitudinal spin Seebeck effect (LSSE) in GGG(Gd 3 Ga 5 O 12 )/GdIG(Gd Fe )/Pt film series exhibiting an in‐plane magnetic easy axis with compensation temperature ( T Comp ) that decreases from 270 to 220 K when decreasing GdIG thickness 272 31 nm, respectively. For all films, LSSE signal flips its sign below . demonstrate universal scaling behavior dependence for films around their respective Additionally, nm grown...
Understanding of spin-heat coupling mechanisms and magnetothermoelectric phenomena, including the anomalous Nernst effect (ANE), in emergent quaternary Heusler alloys is practical importance for applications thermal management energy harvesting. Here, we demonstrate an intrinsic Berry curvature mediated thermopower CoFeVSb, which orders magnetically at high temperature (${T}_{C}\ensuremath{\approx}850\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) with a large saturation magnetization...
The inherent existence of multi phases in iron oxide nanostructures highlights the significance them being investigated deliberately to understand and possibly control phases. Here, effects annealing at 250 °C with a variable duration on bulk magnetic structural properties high aspect ratio biphase nanorods ferrimagnetic Fe3O4 antiferromagnetic α-Fe2O3 are explored. Increasing time under free flow oxygen enhanced volume fraction improved crystallinity phase, identified changes magnetization...
Recently, Heusler alloy-based spin gapless semiconductors (SGSs) with high Curie temperature (TC) and sizable polarization have emerged as potential candidates for tunable spintronic applications. We report comprehensive investigation of the temperature-dependent ANE intrinsic longitudinal Seebeck effect (LSSE) in CoFeCrGa thin films grown on MgO substrates. Our findings show that anomalous Nernst coefficient MgO/CoFeCrGa (95 nm) film is ≈1.86 μV K-1 at room temperature, which nearly 2...
Anomalous Nernst effect (ANE)-based thermopiles can be constructed by combining materials with positive and negative ANE coefficients. While most of the magnetic show ANE, only a limited number exhibit ANE. Furthermore, majority showing have low Curie temperatures (TC). Here, authors demonstrate that high-TC quaternary Heusler alloys large spin polarizations both coefficients, depending on their chemical compositions, hence, potential candidates for developing efficient room-temperature...
The study of magnetoresistance (MR) phenomena has been pivotal in advancing magnetic sensors and spintronic devices. Helimagnets present an intriguing avenue for spintronics research. Theoretical predictions suggest that MR magnitude the helimagnetic (HM) regime surpasses ferromagnetic (FM) by over order magnitude. However, metallic helimagnets like MnP, HM phase remains modest (<10%), limiting its application Here, a groundbreaking approach is presented to achieve giant low-field effect...
We report a comprehensive study of the temperature evolution in-plane (IP) and out-of-plane (OOP) effective magnetic anisotropies in compensated ferrimagnetic ${\mathrm{Fe}}_{100\ensuremath{-}x}{\mathrm{Gd}}_{x}$ alloy films by employing direct current magnetometry radiofrequency (RF) transverse susceptibility (TS) measurements. suggest that our system is chemically inhomogeneous phase segregates into Fe- Gd-enriched regions. Our IP OOP results indicate undergoes temperature-driven...
Understanding the effects of phase transition, coexistence, and surface magnetism on longitudinal spin Seebeck effect (LSSE) in a magnetic system is essential to manipulate charge current conversion efficiency for spincaloritronic applications. We aim elucidate these by performing comprehensive study temperature dependence LSSE biphase iron oxide (BPIO = α-Fe2O3 + Fe3O4) thin films grown Si (100) Al2O3 (111) substrates. A combination temperature-dependent anomalous Nernst (ANE) electrical...
Heusler alloy-based spin gapless semiconductors (SGSs) with very high Curie temperatures $({T}_{C})$ have recently gained enormous attention because of their unconventional electronic structures. They exhibit a nonzero band gap in one the channels and zero other channel, making them an important class materials for tunable transport. Here, we report experimental observation anomalous Nernst effect (ANE) ${\mathrm{Co}}_{1+x}{\mathrm{Fe}}_{1\ensuremath{-}x}\mathrm{CrGa}$ ($x=0$, 0.2, 0.4,...
We report broadband magnetic resonance in polycrystalline Sr2FeMoO6 measured over the wide temperature (T = 10-370 K) and frequency (f 2-18 GHz) ranges. was synthesized by sol-gel method found to be ferromagnetic below TC 325 K. A coplanar waveguide-based spectrometer used record electron spin (ESR) both sweep field modes. From mode at fixed dc fields, we obtain spectroscopic splitting factor g ∼ 2.02 for T ≥ K, which confirms 3+ ionic state of Fe material. The effective value decrease...
Bespoke van der Waals (vdW) crystals provide control over the generation, confinement, and transport of charge, spin, light, heat within between atomically precise two-dimensional (2D) layers. We report a novel functionality in vdW by actuating valence changes metal-organic antiferromagnet through molecular alloying. The quadratic net materials Cr(pyz)2Br2 Cr(pyz)2I2 (pyz = pyrazine) are aliovalent, with different Cr(III) Cr(II) oxidation states due to disparate crystal field potentials...
We report a systematic investigation of the magnetic properties including exchange bias (EB) effect in an iron oxide nanocube system with tunable phase and average size (10, 15, 24, 34, 43 nm). X-ray diffraction Raman spectroscopy reveal presence Fe3O4, FeO, andα-Fe2O3phases nanocubes, which volume fraction each varies depending upon particle size. While Fe3O4phase is dominant all tends to grow increasing size, FeO appears coexist 10, 24 nm nanocubes but disappears 34 nanocubes. The exposed...
We report the magnetization (M), magnetostriction, electrical resistivity (ρ), thermal conductivity (κ) and thermopower (S) of polycrystalline La0.9Na0.1MnO3 over a wide temperature range 5 to 360 K. This sample undergoes paramagnetic ferromagnetic transition around T C = 274 K ρ shows an insulator-metal IM 292 The sign S is positive in entire which indicates that majority charge carriers are holes. Thermopower exhibits peak dip at absence magnetic field. Large difference between...
We report on the effects of annealing temperatures ranging from 225 °C to 325 magnetic properties high aspect ratio iron oxide nanorods consisting a ferrimagnetic Fe3O4 phase and an antiferromagnetic α-Fe2O3 in as-prepared state. Annealing at aforementioned under constant flow O2 for 3 h leads increment volume fraction concomitant enhancement crystallinity phase. These opposing compete with each other, resulting decrease global magnetization increasing temperature. The desirable are achieved...
We report the anomalous Nernst effect (ANE) in polycrystalline metallic perovskite Pr0.5Sr0.5CoO3. The transverse Seebeck coefficient (Sxy) was measured at selected temperatures for magnetic fields up to H = 50 kOe and also as a function of temperature two (H 2 10 kOe). While Sxy increases linearly with above Curie (TC ∼ 229 K), it changes non-linearly low ferromagnetic state exhibits hysteresis similar magnetization. Linear extrapolation high field vs graph zero gives 0.46 µV/K 175 K. It is...
Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI
Tailoring the magnetic properties of iron oxide nanosystems is essential to expanding their biomedical applications. In this study, 34 nm nanocubes with two phases consisting Fe3O4 and α-Fe2O3 were annealed for 2 h in presence O2, N2, He, Ar tune respective phase volume fractions control properties. X-ray diffraction measurements carried out post-treatment evaluate changes treated samples compared as-prepared samples, showing an enhancement O2 while others indicated a enhancement....
Conventionally, the modulation of intrinsic Weyl nodes in semimetals is challenging, due to topological protection. Here we report structural dependence a ${\mathrm{Co}}_{2}\mathrm{MnGa}$ Heusler thin film via temperature-dependent tetragonal distortion. The ability manipulate these allows for control electromagnetic properties. Temperature-dependent x-ray diffraction (XRD) measurements identify compressive distortion with decreasing temperature from 300 20 K. calculated properties can be...