A5047126978- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Microwave Dielectric Ceramics Synthesis
- Advanced Condensed Matter Physics
- Electronic and Structural Properties of Oxides
- Dielectric properties of ceramics
- Magnetic properties of thin films
- High-pressure geophysics and materials
- Magnetic Properties of Alloys
- Earthquake Detection and Analysis
- Nuclear materials and radiation effects
- Crystal Structures and Properties
- Glass properties and applications
- Advanced Memory and Neural Computing
- Dielectric materials and actuators
- Acoustic Wave Resonator Technologies
- Magneto-Optical Properties and Applications
UGC DAE Consortium for Scientific Research
2019-2024
University of California, Berkeley
2024
Indian Institute of Science Bangalore
2023-2024
The structural and dielectric characterization of 30% Sn-doped ${\mathrm{BaTiO}}_{3}$ (${{\mathrm{BaSn}}_{0.3}{\mathrm{Ti}}_{0.7}\mathrm{O}}_{3}$) as a function temperature is carried out combining, complementary probes to reveal modifications associated the relaxor behavior. Dielectric data confirms existence relaxor-type behavior in ${{\mathrm{BaSn}}_{0.3}{\mathrm{Ti}}_{0.7}\mathrm{O}}_{3}$. local average changes have been investigated region broad response. Local probes, such x-ray...
The structural modifications associated with magnetic and multiferroic transitions in ${\mathrm{FeVO}}_{4}$ polycrystalline samples have been investigated using complementary techniques, including synchrotron radiation x-ray diffraction (XRD), Raman spectroscopy, absorption fine-structure spectroscopy (XAFS). Temperature-dependent measurements reveal unveiled details of the local intimately related to spin-lattice coupling. This study is particularly focused on illuminating changes occurring...
A detailed account of magnetolattice coupling, magnetic frustration, and magnetoelectric effects in ${\mathrm{Fe}}_{1\ensuremath{-}x}{\mathrm{Cr}}_{x}{\mathrm{VO}}_{4}$ ($x=0\ensuremath{-}1.0$) studied by temperature-dependent synchrotron x ray diffraction (SXRD), temperature- magnetic-field-dependent dielectric permittivity $\ensuremath{\varepsilon}$, magnetization measurements are presented this paper where progressive Cr doping leads to structural transitions from triclinic...
Abstract Spintronic devices that utilize spin transfer torque are promising for integrated memory applications. However, these face substantial energy consumption challenges due to the high current densities required switching. Conversely, voltage‐driven spintronic devices, using capacitive displacement charge, can realize switching operations energy‐efficient (≈1–10 fJ bit −1 ). This work investigates based on voltage control of interlayer exchange coupling in perpendicular magnetic...
From the phase diagram as proposed by Lei et.al., [J. App. Phys 101, 084105 (2007)] a $BaSn_{0.15}Ti_{0.85}O_{3}$ is chosen showing diffuse transition between cubic to rhombohedral (C-R) near room temperature. Dielectric analysis confirms temperature ($T_{C}$ $\approx$ 290 K) and also frequency dispersion in dielectric constant observed towards low Polarization first-order reversal curves (FORC) suggest that system re-entrant at temperatures. Put together, all these electrical...
We have investigated magnetic, structural and dielectric properties of Bi5FeTi3O15(BFTO) in the temperature range 5K-300 K. Using diffraction, Raman spectroscopy x-ray absorption fine structure measurements, iso-structural modifications are observed at low temperatures (≈100 K). The analysis constant data revealed signatures relaxation, concomitant with these BFTO same temperatures. Further, employing complementary experimental methods, it is shown that distribution Fe/Ti ions random. With...
Here we report the evidence of an additional magnetic ordering and frequency dispersive magneto-dielectric (MD) permittivity besides multiferroic behavior in Te4+(S= 0) doped FeVO4. Two antiferromagnetic transitions similar to FeVO4at ∼21.86 K (TN1) 16.03 (TN2) were observed all samples. An novel defect clusters based at relatively higher temperature (TAMO) ∼ 203 is also from magnetization. Evaluated moments show systematic decrease frustration factors increase with increasing content. MD...
We report the preparation and characterization of vanadium substituted four-layer Aurivillius compound Bi5Fe1.5V0.5Ti2O15 using spin coating method. Ferroelectricity in prepared films are confirmed from well saturated polarization vs electric field (P-E) loops having remnant (2 Pr) around 12.94 µC/cm2 at room temperature. In addition, low temperature P-E measurements show a decrease Pmax 2 Pr, which is attributed to stabilization defect dipole complexes domain pinning, as seen bismuth-based...
The present work reports the ferroelectric (FE) element/site specific spectroscopic measurements in ${\mathrm{BaTi}}_{0.7}^{119}\mathrm{Sn}_{0.3}{\mathrm{O}}_{3}$ relaxor using $^{119}\mathrm{Sn}$ hyperfine interaction studies. properties studied sample are confirmed from macroscopic such as temperature dependent dielectric constant measurements. presence of quadrupole splitting (QS) below its maxima (${T}_{m}$) is unambiguously synchrotron radiation perturbed angular correlation...
Abstract This study demonstrates the magneto‐dielectric (MD) properties of high quality epitaxially strain multiferroic SrMnO 3 thin film on conducting Nb doped SrTiO substrate. The observes considerable positive MD coupling near room temperature and across anti‐ferromagnetic transition . dielectric maxima grown is above temperature, which confirms ferroelectric nature film. From out‐of‐plan polarization PUND (Positive Up Negative Down) measurements in presence magnetic field, it confirmed...
This paper presents study of ferro-elastic a-c domains evolution in BaTiO3 single crystal with electrical poling. The domain populations corresponding to are obtained from x-ray reciprocal space mapping experiments. Our results suggest for different poling fields configurations can be achieved which could help achieving better piezo-electric properties. We’ve also found that a non-linear relationship governs c/a population ratio fields.
We report the structural and magnetic properties of four-layer Aurivillius compound Bi$_5$FeTi$_3$O$_{15}$ (BFTO) at high hydrostatic pressure conditions. The high-pressure XRD data does not explicitly show phase transitions with pressure, however observed changes in lattice parameters indicate modifications different values. In initial region values, $\textit{a}$- $\textit{b}$- are nearly equal implying a quasi-tetragonal structure, as increases diverges apart exhibits complete orthorhombic...
The present work deals with the calculation of electrocaloric (EC) coefficients BaTi1-xSnxO3 (x = 0.15, 0.20, 0.30) polycrystalline ceramics. Dielectric and polarization studies are carried out in a temperature range 100 − 300 K to calculate EC employing indirect method based on Maxwell’s equations. It is demonstrated that effect enhanced near dielectric maxima for all samples, including samples which exhibit relaxor behavior 0.30). Furthermore, maximum change temperature, at coefficient...
The present work reports polarization response and the effects ofac- &dc-fields on 30% Sn doped BaTiO3polycrystalline relaxor thin films as a function of temperature. Apart from low temperature frequency dispersion in dielectric data, independent local maxima constant concomitant peak loss atT* ∼ 245 K is observed, which unusual bulk systems. BelowT*, becomes quite evident showing signatures non-ergodic behavior. Subsequently, responses ergodic (>T*) (<T*) states are studied to determine...