A5030125692- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Solid-state spectroscopy and crystallography
- Multiferroics and related materials
- Magnetic properties of thin films
- Advanced Battery Materials and Technologies
- Conducting polymers and applications
- Advanced NMR Techniques and Applications
- Material Dynamics and Properties
- High-pressure geophysics and materials
- Advanced Thermodynamics and Statistical Mechanics
- Superconducting Materials and Applications
- Magnetic Properties of Alloys
- Electron Spin Resonance Studies
- Crystallography and molecular interactions
- Advancements in Battery Materials
- Iron-based superconductors research
- Luminescence Properties of Advanced Materials
- Inorganic Fluorides and Related Compounds
- Superconductivity in MgB2 and Alloys
- X-ray Diffraction in Crystallography
- Magnetism in coordination complexes
- ZnO doping and properties
- Theoretical and Computational Physics
Indian Institute of Science Bangalore
2013-2024
VTT Technical Research Centre of Finland
2023
Indian Space Research Organisation
2013
University of Cambridge
2012
Building Engineering and Science Talent
2010
Jawaharlal Nehru Centre for Advanced Scientific Research
2008
Bangalore University
2008
Central Electrochemical Research Institute
2008
Defence Research and Development Organisation
2007
Indian Association for the Cultivation of Science
2007
A highly homogeneous ZnO/Ag nanohybrid has been synthesized by a novel route, employing chitosan as mediator purely electrostatic interaction. By various techniques such powder XRD, UV-visible, IR spectroscopy and electron (SEM, TEM) microscopy, the formation of established. The synergistic antibacterial effect on Gram-positive Gram-negative bacteria is found to be more effective, compared individual components (ZnO Ag). Cytotoxicity experiments are carried out results correlated solubility...
Mn2 and Mn5 have been isolated in argon, krypton, xenon matrices their X-band ESR spectra observed at 4 up to 70 K, depending upon the matrix. As predicted by Nesbet, lowest state of is 1Σ, two atoms are exchange coupled (antiferromagnetically). The temperature behavior bands higher spin states (S=1,2,3) was approximately accord with a Lande interval rule, value J=−9±3 cm−1 obtained from S=2 intensity variations. Each fine structure line appears superimposed 11-line hyperfine pattern...
${\mathrm{Nd}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ nanoparticles (average diameter $\ensuremath{\sim}20$ and $40\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) are synthesized by the polymeric precursor sol-gel method characterized various physico-chemical techniques. Quite strikingly, in $20\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ particles, charge-ordered (CO) antiferromagnetic phases observed bulk below $250\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ $160\phantom{\rule{0.3em}{0ex}}\mathrm{K}$,...
We report here the synthesis of water soluble Mn2+-doped CdS nanocrystals in which it has been possible for first time to obtain a distinct Mn2+ d-related emission well-separated from defect state emissions. By varying reaction temperature systematically, we establish 55 °C as optimum maximize d emission, existence this being shown result two opposing influences temperature. Most interestingly, present results that favors preferential doping larger-sized particles even within narrow size...
In the superconducting state, YBa2Cu3O7 absorbs electromagnetic radiation over a wide range of frequencies (8 MHz-9 GHz). The absorption is extremely sensitive to temperature, particle size and magnetic field depends crucially on presence oxygen. A possible explanation for phenomenon based formation Josephson junctions suggested.
We have prepared crystalline nanowires (diameter ~ 50 nm, length a few microns) of the charge ordering manganite Pr_0.5Ca_0.5Mn_O3 using low reaction temperature hydrothermal method and characterized them X-ray diffraction, transmission electron microscopy, SQUID magnetometry magnetic resonance measurements. While bulk sample shows transition at 245 K an antiferromagnetic 175 K, experiments reveal that in phase, ferromagnetic occurs 105 K. Further, disappears is suppressed. This result...
The effect of annealing on structural defects and d0 ferromagnetism in SnO2 nanoparticles prepared by solution combustion method is investigated. as-synthesized were annealed at 400–800 °C for 2 h, ambient conditions. crystallinity, size, morphology the samples studied using x-ray diffraction transmission electron microscopy studies. results grain growth due to coarsening as well reduction oxygen vacancies confirmed Raman spectroscopy, photoluminescence photoelectron spectroscopy. All...
Using electron spin resonance spectroscopy (ESR), we measure the rotational mobility of probe molecules highly diluted in deeply supercooled bulk water and negligibly constrained by possible ice fraction. The increases above putative glass transition temperature water, T(g) = 136 K, smoothly connects to thermodynamically stable region traversing so called "no man's land" (the range 150-235 K), where it is believed that homogeneous nucleation suppresses liquid water. Two coexisting fractions...
Combining experiments with first principles calculations, we show that site-specific doping of Mn into SrTiO3 has a decisive influence on the dielectric properties these doped systems. We find phonon contributions to constant invariably decrease sharply at any site. However, sizable, random dipolar contribution only for Sr site arises from strong off-centric displacement in spite being non-d0 state; this leads large higher temperatures and gives rise relaxor ferroelectric behavior lower...
A unique strategy for scavenging free radicals <italic>in situ</italic> on exposure to gamma irradiation in polyethylene (PE) nanocomposites is presented.
We report electron paramagnetic resonance measurements on single crystalline and powder samples of ${\mathrm{Nd}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ across the charge-ordering transition at ${T}_{\mathrm{co}}=240\mathrm{K}$ down to antiferromagnetic ordering ${T}_{N}=140\mathrm{K}.$ The changes in linewidth, g-factor intensity as functions temperature are studied understand nature spin-dynamics system. explain observed large decrease linewidth from ${T}_{N}$ ${T}_{\mathrm{co}}$...
Three long-standing problems related to the physics of water, viz., possibility vitrifying bulk water by rapid quenching, its glass transition, and supposed impossibility obtaining supercooled between 150 233 K, so-called ``no man's land'' phase diagram, are studied using highly sensitive technique spin probe ESR. Our results suggest that can indeed be vitrified quenching; it undergoes a transition at $\ensuremath{\sim}135\text{ }\text{ }\mathrm{K}$, relaxation behavior this method 165 K...
In this paper, we present the preparation and characterization of nanoparticles nanowires Pr0.5Sr0.5MnO3 (PSMO). The main results investigation are as follows: (a) a comparison with properties bulk material shows that ferromagnetic (FM) transition at 270 K remains unaffected but anti-ferromagnetic (AFM) TN = 150 disappears in nanoparticles, (b) size induced ground state magnetic phase (below K) is predominantly FM, coexisting residual AFM phase, (c) temperature dependence anisotropy complex...
We show from conventional magnetization measurements that the charge order (CO) is completely suppressed in 10 nm Pr(0.5)Ca(0.5)MnO(3)(PCMO 10) nanoparticles. Novel measurements, designed by a special high field measurement protocol, dominant ground state magnetic phase ferromagnetic-metallic (FM-M), which an equilibrium phase, coexists with residual ordered anti-ferromagnetic (CO AFM) (an arrested phase) and exhibits characteristic features of 'magnetic glassy state' at low temperatures. It...