A5089667415- Advanced Condensed Matter Physics
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Multiferroics and related materials
- 2D Materials and Applications
- Iron-based superconductors research
- Electronic and Structural Properties of Oxides
- Rare-earth and actinide compounds
- Crystallization and Solubility Studies
- Magnetism in coordination complexes
- Heusler alloys: electronic and magnetic properties
- X-ray Diffraction in Crystallography
- Theoretical and Computational Physics
- Topological Materials and Phenomena
- MXene and MAX Phase Materials
- Graphene research and applications
- Magnetic properties of thin films
- ZnO doping and properties
- Crystal Structures and Properties
- Magnetic Properties of Alloys
- Shape Memory Alloy Transformations
- Oral and gingival health research
- Transition Metal Oxide Nanomaterials
- Inorganic Chemistry and Materials
- Algebraic structures and combinatorial models
Bennett University
2019-2024
Siksha O Anusandhan University
2020-2024
Vivekananda Global University
2024
Institute of Medical Sciences and Sum Hospital
2023
Centre de Physique Théorique
2017-2019
Université Paris-Saclay
2017-2019
École Polytechnique
2017-2019
Centre de Physique Théorique
2017-2019
Centre National de la Recherche Scientifique
2017-2019
Uppsala University
2014-2018
We report magnetic susceptibility $(\ensuremath{\chi})$ and heat capacity $({C}_{p})$ measurements along with ab initio electronic structure calculations on ${\mathrm{PbCuTe}}_{2}{\mathrm{O}}_{6}$, a compound made up of three-dimensional (3D) network corner-shared triangular units. The presence antiferromagnetic interactions is inferred from Curie-Weiss temperature $({\ensuremath{\theta}}_{\mathrm{CW}})$ about $\ensuremath{-}22$ K the $\ensuremath{\chi}(T)$ data. ${C}_{m}$ data show broad...
Strong spin-orbit coupling (SOC) effects of heavy $d$-orbital elements have long been neglected in describing the ground states their compounds thereby overlooking a variety fascinating and yet unexplored magnetic electronic states, until recently. The entangled electrons such can get stabilized into unusual multiplet $J$-states which warrants severe investigations. Here we show using detailed thermodynamic studies theoretical calculations state Ba$_3$ZnIr$_2$O$_9$, 6$H$ hexagonal perovskite...
We have studied in detail the electronic structure of IrO$_2$ including spin-orbit coupling (SOC) and electron-electron interaction, both within GGA+U GGA+DMFT approximations. Our calculations reveal that Ir t$_{2g}$ states at Fermi level largely retain J$_{\rm eff}$ = $\frac{1}{2}$ character, suggesting this complex entangled state may be robust even metallic IrO$_2$. calculated phase diagram for ground as a function $U$ find metal insulator transition coincides with magnetic change, where...
Tuning the electronic band gaps of semiconductors is at core current research on optoelectronic materials and devices. For ZnO, many studies have tried to enhance gap by chemical substitution, but lattice mismatch often thwarts that approach. Instead, this study looks dimensional reduction. Experiments first-principles calculations reveal not only thickness also...
The efficiency and stability of ${\mathrm{RuO}}_{2}$ in electrocatalysis has made this material a subject intense fundamental industrial interest. surface functionality is rooted its electronic magnetic properties, determined by complex interplay lattice-, spin-rotational, time-reversal symmetries, as well the competition between Coulomb kinetic energies. This was predicted to produce network Dirac nodal lines (DNLs), where valence conduction bands touch along continuous momentum space. Here...
In this work, we report the pressure dependence of effective Coulomb interaction parameters (Hubbard U) in paramagnetic NiO within constrained random phase approximation (cRPA). We consider five different low energy models starting from most expensive one that treats both Ni-d and O-p states as correlated orbitals (dp-dp model) to smallest possible two-orbital model comprising eg only (eg-eg model). find all considered models, bare interactions are not very sensitive compression. However...
We have revisited the valence band electronic structure of NiO by means hard x-ray photoemission spectroscopy (HAXPES) together with theoretical calculations using both GW method and local density approximation + dynamical mean-field theory (LDA+DMFT) approaches. The effective impurity problem in DMFT is solved through exact diagonalization (ED) method. show that LDA+DMFT conjunction standard fully localized limit (FLL) around mean field (AMF) double-counting alone cannot explain all...
Toward the goal of achieving green and sustainable energy conversion storage behaviors, double perovskite oxide materials are always pronounced not only due to their exciting properties but also for advanced catalytic electroactive nature. In order understand factual role either 3d or 4d metal ions in perovskites toward applications, herein we have demonstrated three ruthenium-based disordered perovskites, namely, Ca2MnRuO6 (CMRO), Ca2Mn1.25Ru0.75O6 (CMRO-1), Ca2Mn0.75Ru1.25O6 (CMRO-2), by...
NiS, exhibiting a text-book example of first-order transition with many unusual properties at low temperatures, has been variously described in terms conflicting descriptions its ground state during the past several decades. We calculate these physical within first-principle approaches based on density functional theory and conclusively establish that all experimental data can be understood rather NiS is best as self-doped, nearly compensated, antiferromagnetic metal, resolving age-old...
We have carried out a detailed first-principles study of ${d}^{4.5}$ quaternary iridate ${\mathrm{Ba}}_{3}{\mathrm{YIr}}_{2}{\mathrm{O}}_{9}$ both in its 6H-perovskite-type ambient pressure (AP) phase and also for the high (HP) cubic phase. Our analysis reveals that AP belongs to intermediate spin-orbit coupling (SOC) regime. This is further supported by identification spin moment as primary order parameter (POP) obtained from magnetic multipolar analysis. The large ${t}_{2g}$ bandwidth...
We investigate magnetic, thermal, and dielectric properties of SrCuTe2O6, which is isostructural to PbCuTe2O6, a recently found, Cu-based 3D frustrated magnet with corner sharing triangular spin network having dominant first second nearest neighbor (nn) couplings [B. Koteswararao, et al. Phys. Rev. B 90, 035141 (2014)]. Although SrCuTe2O6 has structurally similar network, but the magnetic data exhibit characteristic features typical quasi -one-dimensional magnet, mainly resulted from...
We explore the effects of electron doping in lanthanum ferrite, ${\mathrm{LaFeO}}_{3}$ by Mo at Fe sites. Based on magnetic, transport, scanning tunneling spectroscopy, and x-ray photoelectron spectroscopy measurements, we find that large gap, charge-transfer, antiferromagnetic (AFM) insulator becomes a small gap AFM band low doping. With increasing concentration, states, which appear around Fermi level, is broadened become gapless critical 20%. Using combination calculations based density...
The electronic structure and magnetic properties of a single Fe adatom on CuN surface have been studied using density functional theory in the local spin approximation (LSDA), LSDA+U approach plus dynamical mean-field (LDA+DMFT). impurity problem LDA+DMFT is solved through exact diagonalization Hubbard-I approximation. comparison one-particle spectral functions obtained from LSDA, show importance correlations for this system. Most importantly, we focused anisotropy found that neither nor can...
We have performed first-principles calculations of the electronic and magnetic properties insulating double perovskite compound ${\mathrm{La}}_{2}{\mathrm{CuRuO}}_{6}$ (LCRO) which has recently been reported to exhibit intriguing properties. derived a tight-binding Hamiltonian for LCRO based on $N\mathrm{th}$-order muffin-tin orbital (NMTO) downfolding technique. The computed on-site energies hopping integrals are used estimate dominant exchange interactions employing an extended...
Green and sustainable energy production through renewable sources is an enormously exciting field of research. Herein, we report A-site lanthanum doped oxygen excess ruthenate (predominantly Ru5+-ions) double perovskite system, CaLaScRuO6+δ (CLSR), as excellent photocatalyst for water splitting. The well characterized polycrystalline compound shows canted antiferromagnetic (AFM) behavior due to the existence disordered Ru-ions at B-site. Based on density functional theory + U (Hubbard U)...
A quantum spin-liquid is a spin disordered state of matter in which spins are strongly correlated and highly entangled with low-energy excitations. It has been often found two-dimensional S = ½, frustrated networks but rarely observed three-dimensional (3D) magnets. Here, KSrFe2(PO4)3, forming complicated 3D lattice moment 5/2, investigated by thermodynamic, neutron diffraction measurements electronic structure calculations. Despite the relatively sizable Curie–Weiss temperature θCW −70 K,...
Exploring the physics of low-dimensional spin systems and their pressure-driven electronic magnetic transitions is a thriving research field in modern condensed matter physics. In this context, recently antiferromagnetic Cr-based compounds such as ${\mathrm{CrI}}_{3}$, ${\mathrm{CrBr}}_{3}$, ${\mathrm{CrGeTe}}_{3}$ have been investigated experimentally theoretically for possible spintronics applications. Motivated by fundamental industrial importance these materials, we studied properties...
The frustrated spin-chain (FSC) systems exhibit exotic ground states and distinct quantum phase transitions. $S=\frac{1}{2}$ FSC is known to the Kosterlitz-Thouless transition from a commensurate gapless fully dimerized gapped upon ratio of next-nearest-neighbor nearest-neighbor coupling $(\ensuremath{\alpha}=\frac{{J}_{2}}{{J}_{1}})$ being tuned. On other hand, $S=\frac{5}{2}$ system show transitions partially incommensurate floating phases [Chepiga, Affleck, Mila, Phys. Rev. B 105, 174402...
Competing magnetic interactions in low-dimensional quantum magnets can lead to the exotic ground state with fractionalized excitations. Herein, we present our results on an S = 5/2 quasi-one-dimensional spin system Bi3FeMo2O12. The structure of Bi3FeMo2O12 consists very well separated, infinite zig-zag chains. observation a broad maximum around 10 K susceptibility suggests presence short-range correlations. Magnetic data do not fit S=5/2 uniform chain model due 2nd nearest-neighbor coupling...
In the present study, we have discussed up-turn behavior in resistivity pattern of topological nodal line semimetal InBi. We argued that such nature could be generalized with a mathematical model, can applied to any compounds exhibiting similar behavior. The extremely high magnetoresistance (XMR) has also been explained by carrier compensation compound, estimated from Hall conductivity. Moreover, study Subhnikov-de Haas (SdH) oscillation and density functional theory (DFT), obtained complete...
The valence electronic structure of the half-metallic double perovskite Sr2FeMoO6 forms from a strongly hybridized band in spin-down channel Fe 3d and Mo 4d states that provides metallic conductivity gapped spin-up channel. ground-state description has previously been explored terms many-body interactions where local nonlocal produce with combination charge-transfer configuration intersite charge fluctuations. Here, we provide qualitative understanding on effects using core-level X-ray...
Using density functional theory, we explore the evolution of electronic and magnetic properties BaRuO3 in four different phases, 9R, 4H, 6H 3C, obtained by synthesizing under pressure conditions. The phases differ differential proportion hexagonal versus cubic close stacking BaO3 layers, leading to important changes structure. By computing optical 4H 9R find that based calculations are a large extent able explain change polytypes.