A5038982385- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- 2D Materials and Applications
- Nuclear materials and radiation effects
- Geological and Geochemical Analysis
- MXene and MAX Phase Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Iron-based superconductors research
- Organic and Molecular Conductors Research
- Iron oxide chemistry and applications
- Gas Sensing Nanomaterials and Sensors
- Metallurgical Processes and Thermodynamics
- Ferroelectric and Negative Capacitance Devices
- Chalcogenide Semiconductor Thin Films
- Graphene research and applications
- Seismology and Earthquake Studies
- Glass properties and applications
- Solid State Laser Technologies
- Inorganic Fluorides and Related Compounds
- Rare-earth and actinide compounds
- Molecular Junctions and Nanostructures
- Luminescence Properties of Advanced Materials
University of California, Santa Barbara
2025
Indian Institute of Science Education and Research Pune
2018-2024
University of Hyderabad
2017
Abstract NiPS 3 is a van der Waals antiferromagnet which has been shown to exhibit spin-phonon and spin-charge coupling in the antiferromagnetically ordered state below T N = 155 K. It also rare Ni-based negative charge-transfer-type insulator with Ni valence linear superposition <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>ψ</mml:mi> <mml:mo>=</mml:mo> <mml:mtext> </mml:mtext> </mml:mrow> <mml:mi>α</mml:mi> <mml:msup> <mml:mi>d</mml:mi>...
Recently, nanolaminated ternary carbides have attracted immense interest due to the concomitant presence of both ceramic and metallic properties. Here, we grow nanolaminate ${\mathrm{Ti}}_{3}{\mathrm{Al}\mathrm{C}}_{2}$ thin films by pulsed laser deposition on c-axis-oriented sapphire substrates and, surprisingly, are found be highly oriented along (103) axis normal film plane, rather than (000l) orientation. Multiple characterization techniques employed explore structural chemical quality...
We investigate the low temperature structural and physical properties of trilayer nickelates R4Ni3O10 (R = La, Pr Nd) using resistivity, thermopower, thermal conductivity, specific heat, high-resolution synchrotron powder X-ray diffraction expansion experiments. show that all three compounds crystallize with a monoclinic symmetry, undergo metal-to-metal (MMT) transition at 135 K (La), 156 (Pr) 160 (Nd). At MMT, lattice parameters distinct anomalies; however, without any lowering symmetry....
The spin-1 triangular lattice Heisenberg antiferromagnet $\mathrm{C}{\mathrm{a}}_{3}\mathrm{NiN}{\mathrm{b}}_{2}{\mathrm{O}}_{9}$ and its sister compounds are conjectured to promote the formation of many-body quantum entangled states such as a spin liquid (QSL), an exotic phase which features fractionalized quasiparticle excitations emergent gauges. We probe single crystal using in-depth Raman spectroscopic technique. Our measurements provide evidence for excitations, suggesting that current...
The pyrochlore iridates (Eu1-xBix)2Ir2O7(0⩽x⩽1) undergo an anomalous negative lattice expansion for small Bi-doping (x⩽0.035) (region I) and a normal forx⩾0.1(region II); this is accompanied by transition from insulating (and magnetically ordered) to metallic with no magnetic ordering) ground state. Here, we investigate using hard x-ray photoemission spectroscopy absorption fine structure (XAFS) spectroscopy. By analyzing the Eu-L3, Ir-L3and Bi-L2&L3edges near edge spectra Eu-3dcore-level...
Single crystals of the triangular lattice antiferromagnet (TLAF) ${\mathrm{Ca}}_{3}{\mathrm{NiNb}}_{2}{\mathrm{O}}_{9}$ and its nonmagnetic analog ${\mathrm{Ca}}_{3}{\mathrm{MgNb}}_{2}{\mathrm{O}}_{9}$ are grown using four-mirror optical floating-zone furnace. By varying growth conditions, two types mm-sized obtained: monoclinic form where ${\mathrm{Ni}}^{2+}$ ${\mathrm{Nb}}^{5+}$ exhibits 1:2 ordering Ni ions (spin 1) arranged on a lattice, orthorhombic ${\mathrm{CaBO}}_{3}$ B site is...
The strongly correlated charge density wave (CDW) phase of 1T-TiSe2 is interest to verify the claims a chiral order parameter. Characterization symmetries critical understand origin its intriguing properties. Here we use very low-power, continuous laser excitation probe by using circular photogalvanic effect. We observe that ground state CDW (D3d) achiral. However, above threshold intensity transforms into nonequilibrium (C3), which changes electronic correlations in material. inherent...
Understanding the electronic behavior of Ni$^{2+}$ in a square planar environment oxygen is key to unravel origin recently discovered superconductivity hole doped nickelate Nd$_{0.8}$Sr$_{0.2}$NiO$_2$. To identify major similarities/dissimilarities between and cuprate superconductivity, study structure Cu$^{2+}$ an identical essential. In order address these questions, we investigate Sr$_2$CuO$_3$ Ni single crystals containing (Cu/Ni)O$_4$ units. Our polarization dependent X-ray absorption...
Trilayer nickelates are a rich class of materials exhibiting diverse correlated phenomena, including superconductivity, density wave transitions, non-Fermi liquid behavior along with an unusual metal-to-metal transition around T* ~ 150 K. Understanding the electronic correlations, lattice and charge dynamics crucial to unreveal origin superconductivity other instabilities in nickelates. Our in-depth Raman measurements shows that trilayer nickelate, La4Ni3O10, from electron-phonon coupled...
The strongly correlated charge density wave (CDW) phase of 1T-TiSe$_2$ is being extensively researched to verify the claims a unique chiral order due presence three equivalent Fermi wavevectors involved in CDW formation. Characterization symmetries therefore critical understand origin their intriguing properties but can be complicated by coupling electronic and lattice degrees freedom. Here we use continuous laser excitation probe TiSe$_2$ using circular photogalvanic effect with very high...
NiPS3 is a Van der Waals antiferromagnet that has been found to display spin-charge and spin-phonon coupling in its antiferromagnetically ordered state below TN = 155 K. Here, we study high-quality crystals of site-diluted Ni1-xZnxPS3 (0 < x 0.2) using temperature-dependent specific heat Raman spectroscopy probes. The site dilution suppresses the antiferromagnetic ordering accordance with mean-field prediction. In NiPS3, show phonon mode P2 (176 cm-1) associated Ni vibrations distinct...
The $T^{\prime}$ infinite layered nickelates have recently garnered significant attention owing to the discovery of superconductivity in hole-doped RNiO$_2$ (R $=$ La, Pr, or Nd), which is $n = \infty$ member series R$_{n+1}$Ni$_n$O$_{2n+2}$. Here, we investigate 3$ member, namely R$_4$Ni$_3$O$_8$ Nd) this family. compound La$_4$Ni$_3$O$_8$ exhibits simultaneous charge/spin-stripe ordering at T$_N^\ast$ 105 K, also concomitant with onset metal-to-insulator (MIT) transition upon lowering...
We have studied the structural, magnetic properties, and electronic structure of compound InCuPO5 synthesized by solid state reaction method. The comprises S = 1/2 uniform spin chains formed corner-shared CuO4 units. Magnetic susceptibility chi(T) data shows a broad maximum at about 65 K, characteristic feature one-dimensional (1D) magnetism. is fitted to coupled, Heisenberg antiferromagnetic (HAFM) chain model that gives intra-chain coupling (J/kB) between nearest neighbour Cu2+ ions as...