A5067159543- Topological Materials and Phenomena
- Advanced Thermoelectric Materials and Devices
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Graphene research and applications
- Advanced Condensed Matter Physics
- 2D Materials and Applications
- Heusler alloys: electronic and magnetic properties
- Quantum and electron transport phenomena
- Magnetic and transport properties of perovskites and related materials
- Advanced Thermodynamics and Statistical Mechanics
- Electronic and Structural Properties of Oxides
- Thermal properties of materials
- Thermal Expansion and Ionic Conductivity
- Perovskite Materials and Applications
- Magnetic properties of thin films
- Phase-change materials and chalcogenides
- Rare-earth and actinide compounds
- nanoparticles nucleation surface interactions
- Acoustic Wave Resonator Technologies
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Mechanical and Optical Resonators
- Metallurgical and Alloy Processes
- Advanced Memory and Neural Computing
Birla Institute of Technology and Science - Hyderabad Campus
2022-2025
Birla Institute of Technology and Science, Pilani
2022-2025
Max Planck Institute for Chemical Physics of Solids
2018-2024
Jawaharlal Nehru Centre for Advanced Scientific Research
2013-2023
Bangalore University
2014-2016
Weyl and Dirac fermions have created much attention in condensed matter physics materials science. Recently, several additional distinct types of been predicted. Here, we report ultra-high electrical conductivity MoP at low temperature, which has recently established as a triple point Fermion material. Here show that the resistivity is 6 n-ohm cm 2 K with large mean free path 11 microns. de Haas-van Alphen oscillations reveal spin splitting Fermi surfaces. In contrast to noble metals similar...
Applying a temperature gradient in magnetic material generates voltage that is perpendicular to both the heat flow and magnetization. This anomalous Nernst effect (ANE) which was thought be proportional value of magnetization for long time. However, more generally, ANE has been predicted originate from net Berry curvature all bands near Fermi level. Subsequently, large thermopower recently observed topological materials with no but around E$_F$. These experiments clearly fall outside scope...
Enhanced electrical transport and ultra low thermal conductivity resulted in a high thermoelectric figure of merit, ZT, ∼1 ∼1.15 at ∼680 K 4 mol% Pb 2 Bi doped AgSbSe2, which are 150 190% higher compared to that the pristine sample, respectively. With this excellent performance, p-type constituting earth abundant Se, offers promise replace traditional metal tellurides containing expensive scarce Te for mid temperature (350–700 K) applications.
The discovery of magnetic topological semimetals has recently attracted significant attention in the field topology and thermoelectrics. In a thermoelectric device based on Nernst geometry, an external magnet is required as integral part. Reported zero-field effect newly discovered hard-ferromagnetic kagome-lattice Weyl-semimetal Co3 Sn2 S2 . A maximum thermopower ≈3 µV K-1 at 80 K zero achieved this Weyl-semimetal. results demonstrate possibility application hard for low-power devices are...
Observation of Weyl and Dirac Fermions in condensed matter systems is one the most important discoveries. Among very few available tools to characterize semimetals through electrical transport, negative magnetoresistance commonly used. Considering shortcomings this method, new chiral anomaly are desirable. We employ planar Hall effect as an effective technique half Heusler semimetal GdPtBi study anomaly. This compound exhibits a large value 1.5 mohm cm resistivity at 2 K 9 T. Our analysis...
Non-symmorphic chiral topological crystals host exotic multifold fermions, and their associated Fermi arcs helically wrap around expand throughout the Brillouin zone between high-symmetry center surface-corner momenta. However, Fermi-arc splitting realization of theoretically proposed maximal Chern number rely heavily on spin-orbit coupling (SOC) strength. In present work, we investigate states a new crystal, PtGa, which has strongest SOC among all reported to date. With comprehensive...
High temperature rocksalt phases of AgBiS2 and AgBiS2-xSex (x = 0.05–0.1) have been kinetically stabilized at room in nanocrytals (∼11 nm) by simple solution-based synthesis. Experimental evidence for this derives from variable powder X-ray diffraction (XRD), photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), analysis. The band gap the nanocrystals (∼1.0 eV) is blue-shifted quantum confinement relative to that cubic bulk phase AgBiS2. Moreover, systematic lower energy...
Halide ion (Cl<sup>−</sup>/Br<sup>−</sup>/I<sup>−</sup>) aliovalently dopes on the Se<sup>2−</sup>sublattice and contributes one n-type carrier in AgBiSe<sub>2</sub>, which gives rise to improved electronic transport properties. A peak<italic>ZT</italic>, value of ∼0.9 at ∼810 K has been achieved for AgBiSe<sub>1.98</sub>Cl<sub>0.02</sub>sample, makes it a promising thermoelectric material mid-temperature applications.
Semiconductors have been fundamental to various devices that are typically operated with electric field, such as transistors, memories, sensors, and resistive switches. There is growing interest in the development of novel inorganic materials for use transistors semiconductor switches, which can be a temperature gradient. Here, we show crystalline semiconducting noble metal sulfide, AgCuS, exhibits sharp dependent reversible p-n-p type conduction switching, along colossal change thermopower...
Abstract Crystalline solids with intrinsically low lattice thermal conductivity (κ L ) are crucial to realizing high‐performance thermoelectric (TE) materials. Herein, we show an ultralow κ of 0.35 Wm −1 K in AgCuTe, which has a remarkable TE figure‐of‐merit, zT 1.6 at 670 when alloyed 10 mol % Se. First‐principles DFT calculation reveals several soft phonon modes its room‐temperature hexagonal phase, also evident from low‐temperature heat‐capacity measurement. These modes, dominated by Ag...
Kagome magnets possess several novel nontrivial topological features owing to the strong correlation between topology and magnetism that extends their applications in field of thermoelectricity. Conventional thermoelectric (TE) devices use Seebeck effect convert heat into electrical energy. In contrast, transverse based on Nernst are attracting recent attention due unique geometry, which uses a single material eliminate need for multitude connections compared conventional TE devices. Here,...
Abstract Weyl semimetal is a unique topological phase with topologically protected band crossings in the bulk and robust surface states called Fermi arcs. nodes always appear pairs opposite chiralities, they need to have either time‐reversal or inversion symmetry broken. When broken minimum number of points (WPs) two. If these WPs are located at level, form an ideal (WSM). In this study, intrinsic ferromagnetic (FM) EuCd 2 As grown, predicted be WSM studied its electronic structure by...
Thermoelectric “waste heat-to-electrical energy” generation is an efficient and attractive option for robust environmentally friendly renewable energy production. Simultaneous tailoring of interdependent thermoelectric parameters, i.e. electrical conductivity, thermopower thermal to improve the figure merit utmost challenge in this field. Another important aspect develop high performance materials based on cheap earth abundant materials. We have chosen AgSbSe2, a homologue AgSbTe2 containing...
The present study demonstrates an ambient solution phase capping free synthesis of superionic AgCuS nanocrystals. Nanoscale size reduction, order–disorder transition and band gap evolution tailor the thermoelectric properties in AgCuS.
NbP shows larger Nernst power factor than its conventional factor, highlighting the potential of topological semimetals for energy conversion based on transverse transport.
Topological Weyl semimetals have recently attracted considerable attention among materials scientists as their properties are predicted to be protected against perturbations such lattice distortion and chemical substitution. However, any experimental proof of robustness is still lacking. In this study, we experimentally demonstrate that the topological ferromagnetic kagomé compound Co3Sn2S2 preserved upon Ni We systematically vary content in single crystals study magnetic anomalous transport...
Topological magnets comprising 2D magnetic layers with Curie temperatures (T
Thermoelectric materials can directly convert waste heat into electrical energy and will play a significant role in future management. Herein, we have achieved improved thermoelectric performance p-type Te-free AgSb1−xCdxSe2 (x = 0.02–0.06) system. Simple doping of Cd2+ the Sb3+ sublattice increases carrier concentration, resulting enhanced conductivity compared to pristine AgSbSe2. Improved transport ultra low thermal give rise high figure merit, ZT, ∼1 at ∼640 K AgSb0.98Cd0.02Se2, which is...
Bulk AgBiS2 crystallizes in a trigonal crystal structure (space group, P3̅m1) at room temperature, which transforms to cation disordered rock salt Fm3̅m) ∼473 K. Surprisingly, solution-grown nanocrystal of metastable Ag/Bi ordered cubic structure, thermodynamically stable disorded 610 Moreover, the order-disorder transition nanocrystalline is associated with an unusual change thermopower. Here, we shed light on origin phase and anomalous thermopower nanocrystals by using combined...
Highly conductive topological semimetals with exotic electronic structures offer fertile ground for the investigation of electrical and thermal transport behavior quasiparticles. Here, we find that layer-structured Dirac semimetal PtSn 4 exhibits a largely suppressed conductivity under magnetic field. At low temperatures, dramatic decrease in by more than two orders magnitude is obtained at 9 T. Moreover, shows both strong longitudinal transverse thermoelectric responses Large power factor...
The interplay between topology and magnetism has recently sparked the frontier studies of magnetic topological materials that exhibit intriguing anomalous Hall Nernst effects owning to large intrinsic Berry curvature (BC). To better understand quantum transport properties these their implications for future applications such as electronic thermoelectric devices, it is crucial discover more novel material platforms performing transverse studies. Here, experimentally demonstrated low-cost...
Topological materials from heavy p-block metal chalcogenides with layered structures and anisotropic bonding are of immense importance for thermoelectrics. The synthesis such simple chemical routes is high significance. Here, we present a low-temperature, facile, one-pot, cost-effective topological insulator Bi2Se3 nanosheets. material demonstrates excellent electrical transport low thermal conductivity, leading to peak thermoelectric figure merit (ZT) ∼0.41 at 480 K. Additionally, the Bi2S3...
The half-Heusler rare-earth intermetallic GdPtBi has recently gained attention due to peculiar magnetotransport phenomena that have been associated with the possible existence of Weyl fermions, thought arise from crossings spin-split conduction and valence bands. On other hand, similar observed in intermetallics often attributed interaction itinerant carriers localized magnetic moments stemming $4f$ shell element. In order address origin GdPtBi, we performed a comprehensive study...