A5087631060- Iron-based superconductors research
- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- Magnetic and transport properties of perovskites and related materials
- Graphene research and applications
- Intellectual Capital and Performance Analysis
- Metal and Thin Film Mechanics
- Advanced Condensed Matter Physics
- ZnO doping and properties
- GaN-based semiconductor devices and materials
- Corporate Taxation and Avoidance
- Magnetism in coordination complexes
- Superconducting Materials and Applications
- Semiconductor materials and interfaces
- Crystal Structures and Properties
- Solid-state spectroscopy and crystallography
- Acoustic Wave Resonator Technologies
- Semiconductor materials and devices
- Quantum many-body systems
- Copper Interconnects and Reliability
- Theoretical and Computational Physics
- Surface and Thin Film Phenomena
- 2D Materials and Applications
Raja Ramanna Centre for Advanced Technology
2019-2025
University of Warwick
2024
Indira Gandhi Centre for Atomic Research
2010-2019
Homi Bhabha National Institute
2018
Indian Institute of Technology Delhi
2011
Max Planck Institute of Microstructure Physics
2011
The occurrence of bulk superconductivity at $\ensuremath{\sim}22\text{ }\text{K}$ is reported in polycrystalline samples ${\text{BaFe}}_{2\ensuremath{-}x}{\text{Ru}}_{x}{\text{As}}_{2}$ for nominal Ru content the range $x=0.75--1.125$. A systematic suppression spin-density-wave transition temperature $({T}_{\text{SDW}})$ precedes appearance system. phase diagram proposed based on measured ${T}_{\text{SDW}}$ and superconducting $({T}_{\text{C}})$ variations as a function composition....
The room temperature growth, characterization, and electrical transport properties of magnetron sputtered superconducting Ti40V60 alloy thin films are presented. exhibit low surface roughness tunable properties. As the sputtering current increases, transition move towards higher temperatures. Rietveld refinement two dimensional XRD (2D XRD) pattern reveals presence stress in films, which shifts from tensile to compressive as increases. Additionally, crystallite size increases with currents....
The room-temperature growth, characterization, and electrical transport properties of magnetron sputtered superconducting Ti40V60 alloy thin films are presented. exhibit low surface roughness tunable properties. As the sputtering current increases, transition moves toward higher temperatures. Rietveld refinement two-dimensional XRD pattern reveals presence stress in films, which shifts from tensile to compressive as increases. Additionally, crystallite size increases with currents. a strong...
Magneto-resistance measurements coupled with positron lifetime measurements, to characterize the vacancy-type defects, have been carried out on topological insulator (TI) system Bi2Se3 of varying Se/Bi ratio. Pronounced Shubnikov-de Haas (SdH) oscillations are seen in nominal Bi2Se3.1 crystals for performed magnetic fields up 15 T 4 K–10 K temperature range, field applied perpendicularly (001) plane crystal. The quantum oscillations, characteristic 2D electronic structure, only that a lower...
Magneto-resistance and Hall resistance measurements have been carried out in fast-cooled single crystals of Bi2Se3−xTex(x = 0 to 2) 4–300 K temperature range, under magnetic fields up 15 T. The variation resistivity with that points a metallic behaviour Bi2Se3, shows an up-turn at low temperatures the Te doped samples. Bi2Se3 show clear signatures Shubnikov–de Hass (SdH) oscillations gets suppressed In Bi2SeTe2 sample, magneto-resistance cusp like positive temperatures, feature associated...
The electronic structure of the cubic and (high pressure) hexagonal phases Eu${}_{2}$O${}_{3}$ have been investigated by means full potential linearized augmented plane wave calculations, within $\mathit{LDA}+U$ method. A structural relaxation was performed for both phases, transition pressure determined. band shows correct insulating character with gap values comparable to experimental ones. contact charge density also calculated (and other Eu compounds) found be in good agreement values....
We report on theoretical calculations of the optical conductivity Ba [Fe(1-x)Co(x)]2 As2, as obtained from density functional theory within full potential LAPW method. A thorough comparison with experiment shows that we are able to reproduce most observed experimental features, in particular a magnetic peak located at about 0.2 eV which ascribe antiferromagnetic ordered stripes. also predict large in-plane anisotropy this feature, agrees very well measurements detwinned crystals. The effect...
In this study we examine the phase transitions in single crystals of [(CH<sub>3</sub>)<sub>2</sub>NH<sub>2</sub>]Co(HCOO)<sub>3</sub>, using magnetization and specific heat measurements as a function temperature magnetic field.
The upper critical field was measured up to 12 T for three BaFe${}_{2\ensuremath{-}\mathrm{x}}$Co${}_{\mathrm{x}}$As${}_{2}$ single crystals with estimated Co concentrations of $x$ $=$ 0.082, 0.117, and 0.143. ${H}_{\mathrm{C}2}$ versus temperature from temperature-dependent resistivity various applied magnetic fields, $H$ \ensuremath{\parallel} $\mathit{ab}$ $c$. [${\mathit{dH}}_{\mathrm{C}2}$/$\mathit{dT}$]${}_{T=\mathit{Tc}}$, normalized the corresponding ${T}_{\mathrm{C}}$, decreases...
The critical current density has been measured on single crystals of Ru-substituted BaFe2As2 superconductor at several temperatures and in fields up to 16 T. magnetization versus field isotherms reveal the occurrence a clear second peak (SMP), also known as fish-tail effect, for both H parallel perpendicular c-axis crystal. in-field resistance data are used draw vortex phase diagram. nature vortices determined from scaling behaviour pinning force extracted JC–H isotherms.
We present Synchrotron XRD measurements on powdered single crystal samples of BaFe2-xRuxAs2 samples, as a function Ru content at room temperature. The Rietveld refinements reveal that the a-axis increases with substitution, while c-axis decreases. variation positional co-ordinates As (zAs), Fe-As bond length and As-Fe-As angles have been determined from refinements. In sample x=0.1, temperature dependent were carried out. results indicate orthorhombicity shows characteristic increase...
We report a comparative magnetotransport study on pristine and annealed Bi2SeTe2 single crystals. The sample shows metallic trend from 300 to 180 K, an insulating behavior for T < whereas the exhibits nature in entire 4.2-300 K temperature range. Magnetoresistance (MR) of samples reveals contrasting behaviour as function (T) magnetic field (B). At 4.2 weak antilocalization (WAL) at low fields transforms localization (WL) (negative MR) B > 2.5 T. Further, quantum MR behaviours seen gradually...
Magneto-transport measurements have been carried out on Bi2−xSbxSe3 (x = 0, 0.05, 0.1, 0.3, 0.5) single crystals at 4.2 K temperature in the magnetic field range of −15 T to 15 T. Shubnikov–de Haas (SdH) oscillations 2D nature were observed samples with Sb concentration upto x 0.3. The analyses SdH magneto-resistance data using Lifshitz–Kosevich equation reveal a systematic decrease Fermi surface area substitution. Berry phase obtained from Landau level fan diagram suggests occurrence...
We investigate the magnetic properties of $S=1$ antiferromagnetic diamond lattice, Ni$X_{2}$(pyrimidine)$_{2}$ ($X$ = Cl, Br), hosting a single-ion anisotropy (SIA) orientation which alternates between neighbouring sites. Through neutron diffraction measurements $X$ Cl compound, ordered state spins are found to align collinearly along pseudo-easy-axis, unique direction created by intersection two easy planes. Similarities in magnetization, exhibiting spin-flop transitions, and susceptibility...
We investigate the magnetic properties of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>S</a:mi><a:mo>=</a:mo><a:mn>1</a:mn></a:mrow></a:math> antiferromagnetic diamond-lattice, <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mi>Ni</b:mi><b:msub><b:mi>X</b:mi><b:mn>2</b:mn></b:msub><b:msub><b:mrow><b:mo>(</b:mo><b:mi>pyrimidine</b:mi><b:mo>)</b:mo></b:mrow><b:mn>2</b:mn></b:msub></b:mrow></b:math> <c:math...
AlN thin films have been grown on Si (100) substrates by reactive ion beam sputter deposition (IBSD) at different substrate temperatures varying from room temperature (RT) to 500oC. Substrate induced microstructural transition amorphous RT, nanocrystalline 300oC microcrystalline 400oC has observed Transmission Electron Microscopy (TEM). Average surface roughness (Ra) and morphology explored using Atomic Force (AFM). UV-VIS spectrophotometry employed probe the changes in optical band-gap (Eg)...