A5045566500- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Perovskite Materials and Applications
- Advanced Condensed Matter Physics
- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
- ZnO doping and properties
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Material Science and Thermodynamics
- Electrocatalysts for Energy Conversion
- Inorganic Chemistry and Materials
- Molecular Junctions and Nanostructures
- Supercapacitor Materials and Fabrication
- Magnetism in coordination complexes
- Copper-based nanomaterials and applications
- Nonlinear Optical Materials Research
- Machine Learning in Materials Science
- Graphene research and applications
- Advanced Thermoelectric Materials and Devices
- Advanced Antenna and Metasurface Technologies
- Organic and Molecular Conductors Research
SRM Institute of Science and Technology
2017-2024
University of Tennessee at Knoxville
2024
SRM University
2017-2022
Oak Ridge National Laboratory
2017
Vanderbilt University
2016-2017
Cornell University
2011-2016
Indian Association for the Cultivation of Science
2007-2011
Uppsala University
2011
Indian Institute of Engineering Science and Technology, Shibpur
2010
National Chemical Laboratory
2007
Abstract Chiral multiferroics offer remarkable capabilities for controlling quantum devices at multiple levels. However, these materials are rare due to the competing requirements of long-range orders and strict symmetry constraints. In this study, we present experimental evidence that coexistence ferroelectric, magnetic orders, crystallographic chirality is achievable in hybrid organic-inorganic perovskites [( R / S )- β -methylphenethylamine] 2 CuCl 4 . By employing Landau mode analysis,...
Nb-doped anatase TiO2 thin films grown by pulsed-laser deposition show Kondo scattering in elctronic-transport measurements, providing evidence for the formation of magnetic moments. The origin magnetism is attributed to cation (Ti) vacancies, confirmed X-ray absorption spectroscopy and first-principle calculations. Ti vacancies are controlled oxygen partial pressure during growth.
Metal–organic frameworks (MOFs) are hybrid crystalline compounds comprised of an extended ordered network made up organic molecules, linkers and metal cations. In particular, MOFs with the same topology as inorganic perovskites have been shown to possess interesting properties, e.g., coexistence ferroelectric magnetic ordering. Using first-principles density functional theory, we investigated effect strain on C(NH2)3Cr(HCOO)3 (CH3CH2NH3)Mn(HCOO)3. Here, show that compressive can...
The recent year has witnessed a flurry of activities in investigating the promising electronic, optical, and transport properties lead‐free double perovskite halides. In present work, structural, Cs 2 (Li/Na)GaI 6 are carefully examined. predicted negative formation energy, absence imaginary frequency phonon spectra, ab‐initio molecular dynamics calculations show that they thermodynamically stable. Additionally, electronic studies employing generalized gradient approximation...
One of the primary objectives in molecular nano-spintronics is to manipulate spin states organic molecules with a d-electron center, by suitable external means. In this letter, we demonstrate first principles density functional calculations, as well second order perturbation thoery, that strain induced change state, from S=1 $\to$ S=2, takes place for an iron porphyrin (FeP) molecule deposited at divacancy site graphene lattice. The process reversible sense application tensile or compressive...
Significance Developments in synthesis and characterizing artificially structured materials have greatly advanced the possibility to explore new states of matter material science. Recent discoveries show that quantum can be achieved at heterointerfaces with various electric mechanical boundary conditions. It remains an open question how design ultrathin layers properties inaccessible bulk phases are amenable technological applications. In this work, we grow heterostructures extremely...
This work investigates the origins of cation ordering double perovskites using first-principles theory computations combined with machine learning (ML) and causal relations. We have considered various oxidation states A, A', B, B' from family transition metal ions to construct a diverse compositional space. A conventional framework employing traditional ML classification algorithms such as Random Forest (RF) coupled appropriate features including geometry-driven key structural modes leads...
Organic-inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead- tin-based hybrids, these systems generally show short lifetimes, correlation framework still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine)2MnCl4, ((R)-3-fluoropyrrolidinium)MnCl3,...
Energy conversion technologies have been developed in response to the depletion of fossil fuels and increasing need for electricity our daily lives. Our study presents pioneering research on ionovoltaic effect 2-dimensional (2D) lead-free perovskite lateral electrode structures separated by millimeter distances. This harnesses moisture adsorption generate electricity. We achieved results leveraging ionic properties Cs3Sb2X9 (X = Cl/Br/I) utilizing a micrometer-thick film. For instance,...
Since the discovery of two-dimensional electron gas (2DEG) at oxide interface LaAlO3/SrTiO3 (LAO/STO), improving carrier mobility has become an important issue for device applications. In this paper, by using alternate polar perovskite insulator (La0.3Sr0.7) (Al0.65Ta0.35)O3 (LSAT) reducing lattice mismatch from 3.0% to 1.0%, low-temperature been increased 30 fold 35,000 cm(2) V(-1) s(-1). Moreover, two critical thicknesses LSAT/STO (001) are found, one 5 unit cells appearance 2DEG and other...
Abstract Polar metals are commonly defined as with polar structural distortions. Strict symmetry restrictions make them an extremely rare breed the constraints favor insulating over metallic phase. Moreover, no known to be magnetic. Here we report on realization of a magnetic metal phase in BaTiO 3 /SrRuO /BaTiO heterostructure. Electron microscopy reveals lattice distortions three-unit-cells thick SrRuO between layers. Electrical transport and magnetization measurements reveal that this...
The technique of coupling cation ordering with other microscopic degrees freedom was employed to induce magnetic polar phenomena within the materials belonging double perovskite oxide family represented by chemical formula AA′BB′O6, i.e., considering occupancy at both 12- and 6-fold oxygen coordinated A- B- sites. Starting from a paraelectric material, La2MnNiO6, that exhibits ferromagnetic behavior near room temperature, we constructed wide composition space search for prospective systems....
Charge-carrier recombination within the photoactive and charge extraction layers is one of major obstacles to achieve high performance perovskite solar cells. Here, we demonstrate an ultrathin layer ZnOS in between SnO2 halide film that can effectively passivate defects, suppressing nonradiative loss. It also helps moderate with increasing surface potential, which facilitates transferring carriers from hole transport layer, consequently providing understanding bottom-up interfacial...
Abstract In this article, we have systematically investigated the structural, electronic, optical and thermoelectric properties of Rb 2 Ag(Ga/In)Br 6 . The resulting negative formation energy along with absence imaginary phonon modes confirm thermodynamic stability addition, derived electronic by using GGA‐PBE + mBJ SOC functional show that direct band gap values are 1.21 eV 1.42 for AgGaBr AgInBr , respectively. Furthermore, dispersed nature leads to their outshining such as higher order...
In ferroelectric-based photovoltaic materials, spontaneous polarization is expected to couple with the electronic and optical properties of such materials have drawn attention as solar cells. Here, we utilize hybrid improper ferroelectricity induce ferroelectric in selected A-site layered B-site rock-salt AA′BB′O6 double perovskites propose an alternate route design semiconductors. First-principles density functional theory calculations ab initio molecular dynamics simulations are performed...
Understanding the nanoscale elastic-size-effects of atomically thin transition-metal dichalcogenides (TMDs) as a function thickness underpins avenue flexible 2D electronics. In this work, we employed atomic force acoustic microscopy (AFAM) technique to investigate thickness-dependent elastic properties CVD grown 2H-MoS2 films. The monolayer MoS2 exhibited Young's modulus 273 ± 27 GPa. Our systematic analysis from bulk suggests that phase exhibits elastic-stiffening behavior with decreasing...
Incorporating a dopant into nanoparticle is nontrivial proposition in view of the size dependent surface versus bulk energy considerations and intrinsic proximity to interior, which facilitates migration surface. If realized controlled, however, it can open up new avenues novel nanomaterials. Some previous studies have shown dopability nanosystems but only with specific functionalization. Here, we demonstrate successful incorporation via route pulsed high electron induced synthesis. We...
Halide perovskites have been widely explored for numerous optoelectronic applications among which phototransistors appeared as one of the most promising light signal detectors. However, it is still a great challenge to endow halide with both mobility and high photosensitivity because their sensitivity moisture in ambient atmosphere. Here, we explore an FAPbBr3 perovskite quantum dot (QD) phototransistor bandlike charge transport measure dark hole 14.2 cm2 V–1 s–1 at Attaining good optical...
TOC figure illustrates the hydorgen evolution and charge storage mechanism of MoWS 2 electrocatalyst/electrode.
Using first-principles density functional calculations, at both generalized gradient approximation (GGA) and $\text{GGA}+U$ levels we have investigated the electronic structure magnetic properties of Fe/Co codoped ZnO nanowire. Here addressed some key issues such as, preferable sites that can occupy, coupling mechanism, role defects in coupling. We found spin alignment between transition-metal atoms depends on their location. When Fe Co are nearest neighbors outer surface nanowire along...
Modulation and δ-doping strategies, in which atomically thin layers of charged dopants are precisely deposited within a heterostructure, have played enabling roles the discovery new physical behavior electronic materials. Here, we demonstrate purely structural "δ-doping" strategy complex oxide heterostructures, manganite inserted into an isovalent host, thereby modifying local rotations corner-connected MnO_{6} octahedra. Combining scanning transmission electron microscopy, polarized neutron...