arXiv subjects

Diwaker

Publications and source records attributed to Diwaker.

At least 19 recordsLinked to original sources

arXiv2025

Density Functional Theory Analysis of Na3AgO: Assessing its Viability as a Sustainable Material for Solar Energy Applications

This study mainly emphasis the fascinating features of inverse perovskites Na3AgO using density functional theory (DFT). Inverse perovskite (IP) Na3AgO structural features have been examined, and the space group and cubic structure of Pm-3m (221) have been confirmed. The experimental formulation and thermal stability of IP have been confirmed by the formation energy. Phonon dispersion curves were used to assess dynamic stability. The dynamic stability of the examined IP and the bonding strength against cubic structure deformation are confirmed by the lack of negative frequencies. The energy gap or the characteristics of semiconducting behaviour have been predicted by the electronic properties of Na3AgO with a band gap of 1.273 eV. In order to confirmthe viability of solar cells, the light-dependent properties have also been identified. Born stability criteria are also used to verify the mechanical stability, and additional elastic characteristics are identified in order to forecast the anisotropy, ductility, strength, and hardness. These anti-perovskites, which possess intriguing characteristics, have the potential to be effective materials for photovoltaic applications, as indicated by the analysed findings.

cond-mat.mtrl-sci↗

arXiv2025

Exploring PdCrAs Half-Heusler Alloy for Sustainable Energy Solutions: An Ab-initio Study

This work presents a comprehensive investigation of the HH alloy PdCrAs using first - principles methods, highlighting its potential applications in various fields, including spintronics, thermoelectrics, and optoelectronics. We employed density functional theory (DFT) within the full potential linearized augmented plane wave (FLAPW) framework. Structural optimizations indicate that the alloy stabilizes in the ferromagnetic phase. Both mechanical and dynamical stability have been confirmed through analyses of elastic constants and phonon dispersion. Our calculations of the electronic band structure and density of states (DOS) reveal that PdCrAs exhibits half-metallic behavior, with a spin-polarized band gap of 0.670 eV in the minority spin channel. The magnetic moment aligns with the Slater Pauling (SP) rule, indicating robust ferromagnetism. Mechanical analysis shows that the material is ductile in nature. Thermodynamic analysis highlights the alloy's resilience, supported by consistent trends in entropy, heat capacity, and Debye temperature.Its optical response demonstrates strong absorption in the visible and ultraviolet (UV) regions, along with pronounced dielectric and plasmonic features, suggesting potential applications in optoelectronics and refracective coatings. Furthermore, evaluations of the transport properties reveal high Seebeck coefficients and a significantly tunable figure of merit (ZT), with values approaching 0.9 across the temperature range of 300 - 1500 K, indicating excellent thermoelectric characteristics. Overall, these findings position PdCrAs as a promising multifunctional material suitable sustainable energy solutions.

cond-mat.mtrl-sci↗

arXiv2025

Thermoelectric Potential of NaVAs Half-Heusler Alloy: Insights from Ab-initio Calculations

This work presents a comprehensive investigation of the HH alloy NaVAs using first - principles methods, emphasizing its potential applications in various fields, including spintronics, thermoelectrics, and optoelectronics. We utilized density functional theory (DFT) within the full-potential linearized augmented plane wave (FLAPW) framework. Structural optimizations indicate that the alloy stabilizes in the ferromagnetic phase. Both mechanical and dynamical stability have been confirmed through analysis of elastic constants and phonon dispersion. Our calculations of the electronic band structure and density of states (DOS) reveal that NaVAs exhibits half-metallic behavior, with a spin-polarized band gap of 2.77 eV in the minority spin channel. The magnetic moment aligns with the Slater Pauling (SP) rule, demonstrating robust ferromagnetism. Mechanical analysis shows that the material is brittle in nature. The thermodynamic analysis highlights the alloy's resilience, supported by consistent trends in entropy, heat capacity, and Debye temperature. Its optical response indicates strong absorption in the visible and ultraviolet (UV) regions, along with pronounced dielectric and plasmonic features, suggesting potential for applications in optoelectronics and refective coatings. Furthermore, evaluations of the transport properties show high Seebeck coefficients and a significantly tunable figure of merit (ZT). ZT values approach 1.0 across the temperature range of 600 - 1500 K, demonstrating excellent thermoelectric characteristics. Overall, these findings position NaVAs as a promising multifunctional material suitable for advanced technological applications in green energy area.

cond-mat.mtrl-sci↗

arXiv2025

Computational insights into Cobalt-based novel half-Heusler alloy for sustainable energy applications

The quest for efficient and sustainable green energy solutions has led to a growing interest in half Heusler alloys, particularly for thermoelectric and spintronic applications. This study investigates the multifaceted nature of cobalt based half Heusler alloy, CoVAs, employing DFT with advanced computational techniques, such as the FLAPW method. The elastic, electronic, magnetic, thermodynamic, and optical properties of CoVAs are meticulously analyzed. Structural and mechanical evaluations reveal mechanical stability and brittleness under varying pressures. Electronic and magnetic properties are examined through band structure and DOS analysis, revealing a half metallic nature with a minority spin band gap. The total magnetic moment aligns with the Slater Pauling rule, further confirming ferromagnetism and half metallicity. Thermodynamic investigations, based on the quasi-harmonic Debye approximation, provide insights into temperature- and pressure dependent behavior, including thermal expansion, heat capacity, and Debye temperature, establishing CoVAs as a viable candidate for high temperature applications. Additionally, the optical properties underestimate its potential in optoelectronic applications due to high absorption in the UV region, showing a distinct absorption edge corresponding to the electronic band gap. Phonon dispersion relations reflect the stability of the alloy, and the figure of merit confirms the alloy's suitability for thermodynamics applications. The findings highlight the potential of CoVAs as a promising candidate for spintronic photovoltaic and optoelectronic applications, providing insights into its fundamental properties that could facilitate experimental synthesis and industrial implementation for green energy and advanced technological applications.

cond-mat.mtrl-sci↗

arXiv2025

Computational Studies of NaVTe Half Heusler Alloy for Green Energy Applications

To lessen the quick depletion of fossil fuels and the resulting environmental harm, it is necessary to investigate effective and eco-friendly materials that can convert lost energy into electricity. The structural, optical, electronic, thermo-electric, and thermodynamic properties of the novel half-Heusler (HH) material NaVTe were examined in the current work using density functional theory (DFT). The Birch-Murnaghan equations of states were used to confirm the structural stability of the NaVTe HH alloy under investigation. These equations show that the compound in question has structural stability because its ground-state energy levels are negative. For spin-down configurations, NaVTe possesses an energy band gap of 3.2 eV, according to band structure and total density of state analysis. NaVTe is a material that is desirable for optoelectronic applications due to its optical features, which include maximum conductivity and absorption of electromagnetic radiation. The figure of merit and other thermodynamic and thermoelectric parameters are calculated. According to these predicted outcomes, the NaVTe HH alloy would be the ideal option for thermo-electric and renewable energy applications.

cond-mat.mtrl-sci↗

arXiv2024

First Principle Analysis of Novel Half Heusler Alloys VPdZ (Z= Ge, Sn) for thermodynamic, spintronics and optoelectronic applications

This study explores the structural stability, elastic, mechanical, electronic, thermophysical, magnetic, optical and lattice dynamic properties of VPdZ (Z= Ge, Sn) half Heusler alloys using density functional theory. The alloys show stability in type-{\alpha} ferromagnetic phase and have half-metallic band topologies. The half-metallic feature is indicated by the spin-polarized behavior that is revealed by the detailed profiles of the electronic band structures. According to the electronic band profiles both alloys are half-metallic, with indirect energy gaps in the spin down channel of 1.10 eV and 1.02 eV for VPdGe and VPdSn half Heusler alloys respectively. The Quasi-Harmonic Debye model helps study thermodynamic parameters, and the magnetic moment values align with the Slater-Pauling rule. The alloys have potential applications in thermodynamic, spintronic, and optoelectronic fields.

cond-mat.mtrl-sci↗

arXiv2024

First-principles investigation of multifaceted properties; lattice dynamic, structural stability, mechanical, electronic, magnetic and thermodynamic response of Alkali metals-based semi Heusler alloys

Taking into considerations the wide compositional stretch of Heusler alloys, the first principles density functional theory based calculations are excellently suitable for estimating the multifaceted properties of alkali metal based LiVSb and NaVSb Heusler alloys. We calculated ground state stability by optimizing the energy in alpha, beta and gamma phase configurations. The materials are dynamically stable in spin polarised phase type alpha. To explore the electronic structure, we successfully employed the generalized gradient approximation potential. The electronic band structures indicate a half-metallic nature featuring a wide indirect band gap of 1.40eV and 1.45eV. We computed the second-order elastic parameters at different pressure levels. The Pugh ratio less than 0.25 assessed that both alloys are brittle in nature and mechanically stable. The obtained magnetic moment is consistent with the Slater-Pauling rule. By executing the Quasi-Harmonic Debye model and Boltzmann theory we assessed the various thermodynamic parameters and transport coefficients of both alloys at different temperatures and pressures. All positive frequencies in lattice dynamic study confirmed their stability. Our findings highlight the potential of these alloys in modern semiconductor technology, and thermoelectric applications.

cond-mat.mtrl-sci↗

arXiv2024

Spin-polarized DFT calculations for physical properties of novel KVSb half-Heusler compound for spintronic and thermodynamic applicability

In the reported study we have investigated the robust phase stability, elasto-mechanical, thermophysical and magnetic properties of KVSb half Heusler compound by implementing density functional theory models in Wien2k simulation package. The dynamic phase stability is computed in phase type I, II & III phase configurations by optimising their energy. It is observed that given compound is more stable in spin-polarised state of phase type I. To explore the electronic band structure, we apply the generalised gradient approximation. The electronic band profile of the Heusler alloy display a half-metallic nature. Moreover, the calculated second-order elastic parameters divulge the ductile nature. To understand the thermodynamical and thermoelectric stability of the alloy at various temperature and pressures ranges we have utilised the Quasi-Harmonic Debye model. The computed value of magnetic moment found in good agreement with Slater-Pauling rule. Our findings confirms that the predicted half Heusler alloy can be used in various spintronics and thermoelectric applications.

cond-mat.mtrl-sci↗

arXiv2024

Investigations of the Effects of Pressure on the Structural and Electronic Properties of Co$_2$VZ (Z = Al, Be) Full Heusler Alloy: A Comparative Study Using DFT

This study focuses on the investigations and comparative study of the electronic structure of Co$_2$VZ (Z=Al, Be) Heusler alloys under varying high pressure conditions. The pressure range explored spans from 0.0 GPa to 30.0GPa, with increments of 0.5GPa. The WIEN2K simulation program is used to investigate the effect of pressure on the structural, magnetic, and electronic properties of Co$_2$VZ Heusler alloys. The WIEN2K simulation code with WC-GGA and mBJ exchange correlation potentials are used to investigate various features. The results of the WC-GGA exchange correlation potentials are then compared to earlier experimental and theoretical findings employed different exchange correlation potentials. The stability observed in the P-V plot indicates the absence of any structural phase transition from a cubic symmetry structure to another structural phase. The varying slopes observed in the band gap response to increasing pressure in different pressure ranges for studied alloys can be attributed to the predominance of either permittivity or quantum confinement effects.

cond-mat.mtrl-sci↗

arXiv2024

Ab-initio investigations of novel potential all-d metal Heusler alloys Co$_2$MnNb

In this study, we employ the Wien2k code to conduct ab-initio study of a novel potential all-d-metal Heusler alloy Co$_2$MnNb. The analysis utilizes the comparison of local spin density approximations (LDA) with Perdew-Burke-Ernzerh parameterized Generalized Gradient Approximation (PBE-GGA) for structural optimization while modified Becke-Jones potential (mBJ) exchange-correlation potentials to examine various characteristic properties of the alloy under study. Employing Birch-Murnaghan equation of state, we construct the energy-versus-volume curve, facilitating the determination of stable phases and structural parameters of the investigated alloys. Structural optimization in both non-magnetic (NM) and spin-polarized (FM) states reveals the stability of the alloy in the FM state. The compound exhibits metallic behavior in bulk, with notable anisotropic semiconducting behavior for down spin while pure metallic behavior for up spin electrons. Partial density of states of each element of the composition is also analysed to compare their respective contribution towards the observed band structure. The anisotropic behavior of Co$_2$MnNb for a specific spin state could be of importance in future spintronic and other thin films device applications.

cond-mat.mtrl-sci↗

arXiv2024

Effects of metals (X = Zn, Co) on structure, electronic bands and gravimetric capacity of KXH$_3$ hydrides

Using the WIEN2K code, the hydrogen storage capabilities of lithium-based KXH$_3$ (X = Zn, Co) hydrides perovskites are examined. To verify the stability of these hydrides, first-principles simulations are employed to examine their structural, electronic, and hydrogen storage capabilities. These compositions' structural investigation shows that the hydrides are stable and part of the cubic space group (221 Pm-3m). We have examined several aspects of these composition's features throughout, using the Perdew-Burke-Ernzerhof generalized gradient approximation. The study identifies stable phases and structural parameters of hydrides using B-E equations, assessing thermodynamic stability in terms of hydrogen storage capacities. The metallic nature of these hydrides is confirmed through band structure and density calculations using WIEN2K.

cond-mat.mtrl-sci↗

arXiv2024

Effects of metals (X = Pd, Ag, Cd ) on structural, electronic, mechanical, thermoelectric and hydrogen storage properties of LiXH$_3$ perovskites

Using the WIEN2K code, the hydrogen storage capabilities of lithium compositions like LiXH$_3$ (X = Pd, Ag, Cd) hydrides are examined. Structural, electrical, mechanical, thermoelectric, and hydrogen storage properties of these hydrides are analyzed using first-principles simulations to verify their stability. Structural analysis of these compositions reveals that the hydrides are stable and belong to the cubic space group number (221 Pm-3m). The thermodynamic stability of these hydrides are given in terms of gravimetric hydrogen storage capacities. The purpose of the study is to calculate heating of formation and breakdown temperature to determine stability of these hydrides. The metallic nature of all compositions are confirmed by band plots and density of states. The elastic properties such as elastic constant, Pugh's ratio, bulk modulus, Poisson's ratio and anisotropy factor are calculated to check the applicability of these compositions for applications involving hydrogen storage. The present paper represents the initial theoretical approach toward the future exploration of these materials for hydrogen storage applications.

cond-mat.mtrl-sci↗

arXiv2024

First-principle screening of structural, electronic and hydrogen storage properties of Vanadium based hydride perovskites XVH$_3$ (X = Li, K)

V-based XVH$_3$ (X = Li,K) hydrides perovskites are investigated for their hydrogen storage capacity using the WIEN2K code. To verify the stability of these hydrides, first-principles investigations are employed to examine their structural, electronic and hydrogen storage properties. According to structural studies these compositions hydrides are stable and part of the cubic space group (221 Pm-3m). We have examined many aspects of these compositions throughout, using the PBE-GGA exchange correlation potential. We obtained the energy versus volume curve and found the stable phase and structural parameter of these hydrides using equation of state given by Birch-Murnaghan's. These hydrides thermodynamic stability is expressed in terms of their gravimetric hydrogen storage capacity.The goal of this study is to compute the standard enthalpy of formation and thermal desorption to ascertain the stability of these hydrides. Based on band structure and density of state plots it is found that these compositions are metallic in nature. The study presents a preliminary theoretical approach for hydrogen storage applications of thermoelectric compositions, revealing their strong thermoelectric responses and potential for green energy sources.

cond-mat.mtrl-sci↗

arXiv2017

Exact solution of long-range electron transfer through conjugated molecular bridge

Intermolecular electron transfer reaction often occurs over long range distances (i.e. up to several tens of angstroms) and plays a key role in various physical, chemical and biological processes. In these reactions the rate constant of long range electron transfer depends upon electronic coupling between the donor and acceptor. The coupling between donor and acceptor may increases by the atoms located between them which form a kind of bridge for electron tunneling. By using exact analytical method we calculated the value of electronic coupling for the above said processes in which the interaction of an electron with the donor, acceptor are represented as Dirac delta functions and conjugated bridge is represented by finite square well.

physics.chem-ph↗

arXiv2015

Some exact results for the Smoluchowski equation for a parabolic potential with time dependent delta function sink

The Smoluchowski equation with a time dependent delta function sink is solved exactly for many special cases. In all other cases the problem can be reduced to an integral equation. It is shown that by knowing the probability distribution at the position of sink, one can derive analytical expression for probability distribution everywhere. Thus the problem is reduced from a PDE in two variables to an integral equation of one. As far as the authors knowledge, we are the first one to provide an exact analytical solution of Smoluchowski equation for a parabolic potential with time dependent sink.

cond-mat.stat-mech↗

arXiv2014

Diffusion under a flat potential with time dependent sink

The Smoluchowski equation for a free particle with a time dependent sink is solved exactly for many special cases. In this method by knowing the probability distribution at the origin P(0,t), one may derive the probability distribution at all positions i.e. P(x,t)

quant-ph↗

arXiv2014

Exact results on diffusion in a piecewise linear potential with a time dependent sink

The Smoluchowski equation with a time dependent sink term is solved exactly. In this method by knowing the probability distribution at the origin P(0,s), one may derive the probability distribution at all positions i.e., P(x,s). Further the exact solution for Smoluchowski equation are also provided in different cases where the sink term has linear, constant, inverse and exponential variation in time.

quant-ph↗

arXiv2013

Non-adiabatic transition probability with a moving $\delta$ potential coupling

The present work focuses on the calculation of a non-adiabatic transition probability between two states which may or may not cross with each other and are coupled to each other by a moving $\delta$ function potential. Here, the time dependent Schrodinger equation is converted to time independent one by using a scaling factor which is function of time. This time independent Schrodinger equation is then considered for two potentials coupled by a moving $\delta$ potential and an expression for non-adiabatic transition probability has been derived.

quant-ph↗