arXiv subjects

F. Parvin

Publications and source records attributed to F. Parvin.

At least 19 recordsLinked to original sources

arXiv2026

Physical properties of transition metal hydride superconductors Mg2TmH6 (Tm = Rh, Pd, Ir, Pt) by first-principles calculations

In this work, a comprehensive first-principles investigation of the structural, hydrogen storage potential, electronic, elastic, mechanical, thermophysical, superconducting, and optical properties of Mg2TmH6 (Tm = Rh, Pd, Ir, Pt) hydrides is presented. Obtained results demonstrate that Mg2TmH6 hydrides combine favorable hydrogen storage, mechanical robustness, superconductivity, and multifunctional optical properties, making them promising candidates for energy storage, superconducting and advanced optoelectronic applications.

cond-mat.mtrl-sci↗

arXiv2025

Ab-initio Study of Structural, Magnetic, Optoelectronic and Thermo-Physical Properties of HoPdBi Half-Heusler Semimetal

In this investigation, we have used the density functional theory (DFT) to investigate several aspects of the half-Heusler compound HoPdBi. The following properties have been studied: spin polarized electronic properties, magnetic moment, phonon dispersion with phonon density of states, structural, elastic properties, optical characteristics, and thermo-physical features. The calculated unit cell volume and ground-state lattice characteristics closely match the experimental results. This study is the first to examine the optoelectronic, thermo-physical, and elastic characteristics of HoPdBi. The mechanical stability requirements were met by the calculated elastic constants. The compound's ductility is shown by the estimated Pugh's ratio, Poisson's ratio, and Cauchy pressure. Band structures and electronic energy density of states have been evaluated in order to better understand the magnetic features with spin polarization. Band structure simulations were conducted with and without the spin-orbit coupling (SOC) effect in order to look into any topological signature. The electrical band structure of the compound shows semi-metallic properties. The reflectivity, absorption coefficient, refractive index, dielectric function, optical conductivity, and loss function of this semi-metal have all been thoroughly examined. The compound is a good reflector in infrared region and a good absorber of ultraviolet (UV) light. This compound is a suitable candidate for high temperature applications and possesses potential as heat sink because of its high melting point and thermal conductivity. It is also suitable for spintronics applications. The majority of this study's findings are completely novel.

cond-mat.mtrl-sci↗

arXiv2024

Ab-initio insights into the mechanical, phonon, bonding, electronic, optical and thermal properties of hexagonal W2N3 for potential applications

We investigated the structural, elastic, electronic, vibrational, optical, thermodynamic and a number of thermophysical properties of W2N3 in this study using DFT based formalisms. The mechanical and dynamical stabilities have been confirmed. The Pugh and Poisson ratios are located quite close to the brittle to ductile borderline. The electronic band structure and energy density of states show metallic behavior. The Fermi surface features are investigated. The analysis of charge density distribution map clearly shows that W atoms have comparatively high electron density around than the N atoms. Presence of covalent bondings are anticipated. High melting temperature and high phonon thermal conductivity at room temperature of W2N3 imply that the compound has potential to be used as a heat sink system. The optical characteristics demonstrate anisotropy for W2N3. The compound can be used in optoelectronic device applications due to its high absorption coefficient and low reflectivity in the visible to ultraviolet spectrum. Furthermore, the quasiharmonic Debye model is used to examine temperature and pressure dependent thermal characteristics for the first time.

cond-mat.mtrl-sci↗

arXiv2024

Pressure dependent physical properties of a potential high-TC superconductor ScYH6: insights from first-principles study

We have investigated the structural, elastic, electronic, thermophysical, superconducting, and optical properties of ScYH6 under uniform hydrostatic pressures up to 25 GPa, using the density functional theory (DFT) formalism. Most of results reported here are novel. The compound ScYH6 has been found to be elastically and thermodynamically stable within the pressure range considered. The compound is brittle; the brittleness decreases with increasing pressure. The elastic anisotropy is low and the machinability index is moderate which increases gradually with rising pressure. The compound is a hard material. The electronic band structure shows weakly metallic character with low density of states at the Fermi level. The Debye temperature of the compound is high and increases with increasing pressure. The Gr\"uneisen parameter of ScYH6 is low and the phonon thermal conductivity is high at room temperature. The compound is a very efficient reflector of infrared radiation. The compound is also an efficient absorber of visible and ultraviolet light. The overall effect of pressure on optical parameters is small. We have also investigated the pressure induced changes in the predicted superconducting state properties by considering the changes in the electronic density of states at the Fermi level, Debye temperature, and the repulsive Coulomb pseudopotential. The superconducting transition temperature is found to increase gradually with increasing pressure.

cond-mat.mtrl-sci↗

arXiv2023

First-principles pressure dependent investigation of the physical properties of KB2H8: a prospective high-TC superconductor

Using the density functional theory (DFT) based first-principles investigation, the structural, mechanical, hardness, elastic anisotropy, optoelectronic, and thermal properties of cubic KB2H8 have been studied within the uniform pressure range of 0 - 24 GPa. The calculated structural parameters are in good agreement with the previous theoretical work. The compound KB2H8 is found to be structurally and thermodynamically stable in the pressure range from 8 GPa to 24 GPa. Single crystal elastic constants Cij and bulk elastic moduli (B, G and Y) increase systematically with pressure from 8 GPa to 24 GPa. In the stable phase, KB2H8 is moderately elastically anisotropic and ductile in nature. The compound is highly machinable and fracture resistant. The Debye temperature, melting temperature and thermal conductivity increases with pressure. The results of electronic band structure calculations and optical parameters at different pressures are consistent with each other. The compound is optically isotropic. The compound KB2H8 has potential to be used as a very efficient solar energy reflector. The electronic energy density of states at the Fermi level decreases systematically with increasing pressure. The same trend is found for the repulsive Coulomb pseudopotential. Possible relevance of the studied properties to superconductivity has also been discussed in this paper.

cond-mat.mtrl-sci↗

arXiv2023

Ab-initio insights into the structural, elastic, bonding, and thermophysical properties of UHx (x = 1, 2, 3, 5, 6, 7, 8) under pressure: possible relevance to high-Tc superconductivity

Binary uranium hydrides, UHx (x = 1, 2, 3, 5, 6, 7, 8), with different crystal symmetries are potentially interesting compounds for high-Tc superconductivity and as hydrogen storage systems. In this work we have explored the structural, elastic, mechanical, bonding, and thermophysical properties of these systems under uniform pressure via density functional theory based computations. Most of the results disclosed in this work are novel. From the calculations of the cohesive energy and enthalpy of formation, we have found that the titled compounds are chemically stable. The computed elastic constants at different pressures ensure elastic stability. All the binary hydrides are mechanically anisotropic. Pressure induced brittle-ductile transition takes place under high pressure. The compounds are machinable with the cubic {\alpha}-UH3-Pm-3n showing very high value of the machinability index. All the compounds are fairly hard with cubic UH8 showing superhard character. The Debye temperatures and acoustic velocities of these compounds are high; the highest value is found for the cubic UH8. The melting temperature, Gr\"uneisen parameter, minimal phonon thermal conductivity, and the thermal expansion coefficient of these compounds have also been studied at different pressures. All these parameters show excellent correspondence with the estimated Debye temperature, elastic parameters and bonding characteristics.

cond-mat.mtrl-sci↗

arXiv2023

Structural, elastic, electronic, bonding, thermo-mechanical and optical properties of predicted NbAlB MAB phase in comparison to MoAlB: DFT based ab-initio insights

In this study, we have used density functional theory (DFT) based first-principles investigation of the physical properties of prospective NbAlB compound for the first time. From the analysis of the cohesive energy and enthalpy of formation, it was found that NbAlB is chemically stable. The physical properties of NbAlB have been compared and contrasted with those obtained for MoAlB. Both these MAB phases are elastically anisotropic, mechanically stable, machinable and brittle materials. Structural and elastic features reflect the layered features. The estimated hardness of NbAlB is 19.0 GPa comparable to that of MoAlB (20.8 GPa) suggesting that predicted NbAlB is a hard compound and is suitable for heavy duty industrial applications. NbAlB is more machinable than MoAlB. Electronic band structure calculations reveal conventional metallic behavior with the electronic density of states at the Fermi level arising mainly due to the Nb 4d orbitals in NbAlB. The electronic density of states at the Fermi level is significantly higher in NbAlB in comparison to MoAlB, indicating that NbAlB is expected to exhibit higher level of electrical conductivity. Electronic dispersion is highly anisotropic for both MoAlB and NbAlB with substantially large electronic effective masses in the out-of-plane directions. The bonding features have been elucidated via the analysis of the band structure and charge density distribution. Both the compounds have mixed covalent, ionic and metallic bonding characteristics. The Fermi surfaces of MoAlB and NbAlB consists of electron and hole like sheets. The Debye temperatures of MoAlB and NbAlB are comparable. The estimated melting temperature of NbAlB is somewhat lower than that of MoAlB. NbAlB shows excellent reflection characteristics suitable to be used as an efficient solar reflector. NbAlB is also expected to absorb ultraviolet radiation very effectively.

cond-mat.mtrl-sci↗

arXiv2022

Ab-initio insights into the pressure dependent physical properties and possible high-Tc superconductivity in monoclinic and orthorhombic MgVH6

Here we have used the density functional theory (DFT) with the GGA-PBE approximation to investigate the structural, mechanical, electronic, hardness, thermal, superconductivity and optoelectronic properties under pressure for monoclinic (P21/m) and orthorhombic (Pmn21) structures of MgVH6. We have studied optical properties of P21/m phase at 0 GPa and Pmn21 phase at 100 GPa only (considering phase stability). Both of the phases of MgVH6 are thermodynamically stable. P21/m phase is mechanically stable but Pmn21 is mechanically unstable in our calculations for the pressures considered. Monoclinic (P21/m) is ductile in nature, on the other hand, orthorhombic (Pmn21) is brittle in nature at 100 GPa and becomes ductile for pressures in the range from 125 GPa to 200 GPa. Hardness calculations indicate superhard character of orthorhombic (Pmn21) structure at 100 GPa. The melting temperature of orthorhombic crystal is very high. This also agrees with the bulk modulus, Debye temperature, and hardness calculations. We have calculated theoretically the superconducting transition temperature Tc at different pressures only for the orthorhombic (Pmn21) structure following a previous study. The estimated values of transition temperatures are within 104.7 K to 26.1 K in the pressure range from 100 GPa to 200 GPa. MgVH6, in both the structures, are elastically and optically anisotropic.

cond-mat.mtrl-sci↗

arXiv2020

Pressure dependence of structural, elastic, electronic, thermodynamic, and optical properties of van der Waals-type NaSn2P2 pnictide superconductor: insights from DFT study

NaSn2P2 is a recently discovered superconducting system belonging to a particular class of materials with van der Waals structure. There is enormous interest in such compounds because of their intriguing electrical, optical, chemical, thermal, and superconducting state properties. We have studied the pressure dependent structural, thermo-physical, electronic band structure, and superconducting state properties of this quasi-two dimensional system in details for the first time via ab initio technique. The optical The optical properties are also investigated for different electric field polarizations for the first time. The elastic anisotropy indices point towards high level of mechanical and bonding anisotropy in NaSn2P2 consistent with its highly layered structure. The pressure dependent superconducting transition temperature, Tc, of NaSn2P2 is predicted to vary strongly with the pressure dependent variation of Debye temperature. The electronic energy dispersion curves reveal high level of direction dependence; the effective mass of charge carries are particularly high for the out-of-plane charge transport. The optical parameters compliment the underlying electronic energy density of states features and are weakly dependent on the polarization of the incident electric field. The reflectivity of NaSn2P2 is very high in the visible region and remains quite high and non-selective over an extended energy range in the ultraviolet region. The absorption coefficient is also high in the mid-ultraviolet band. All these optical features render NaSn2P2 suitable for optoelectronic device applications.

cond-mat.mtrl-sci↗

arXiv2020

Mechanical, optoelectronic and thermoelectric properties of half-Heusler p-type semiconductor BaAgP: A DFT investigation

We have explored the mechanical, electronic, optical and thermoelectric properties of p-type half-Heusler compound BaAgP for the first time using density functional theory based calculations. The mechanical and dynamical stability of this compound is confirmed by studying the Born stability criteria and phonon dispersion curve, respectively. It is soft, ductile and elastically anisotropic. The atomic bonding along a-axis is stronger than that along c-axis. The calculated electronic structure reveals that the studied compound is an indirect band gap semiconductor. The analysis of charge density distribution map and Mulliken population reveals that the bonding in BaAgP is a mixture of covalent and ionic. The optical features confirm that BaAgP is optically anisotropic. The high absorption coefficient and low reflectivity in the visible to ultraviolet region make this compound a possible candidate for solar cell and optoelectronic device applications. The thermoelectric properties have been evaluated by solving the Boltzmann semi-classical transport equations. The calculated power factor at 1000K along a-axis is 35.2 micro-W/cmK2 (with tau=10-14 s) which is ~3.5 times larger than that of SnSe, a promising layered thermoelectric materials. The thermoelectric figure of merit, ZT of BaAgP is 0.44 which is small due to high thermal conductivity. So the reduction of thermal conductivity is essential to enhance thermoelectric performance of BaAgP in device applications.

cond-mat.mtrl-sci↗

arXiv2018

Structural, Elastic, Electronic, Thermodynamic, and Optical Properties of Layered BaPd2As2 Pnictide Superconductor: a First Principles Investigation

BaPd2As2 belongs to 122 pnictide group, famous for exhibiting superconductivity at high temperatures and other electronic correlations. Unlike the 122 iron arsenides, BaPd2As2 exhibits superconductivity at low temperature when realized in theThCr2Si2 type structure (I4/mmm). We have performed density functional theory (DFT) based calculations to investigate the structural, elastic, electronic, thermodynamic, and optical properties of BaPd2As2 in this study. The structural, elastic, and the band structure features are compared with the available experimental and theoretical results. Pressure and temperature dependences of various important thermodynamic functions, e.g., bulk modulus, specific heats at constant pressure and volume, coefficient of volume thermal expansion, and Debye temperature are studied in details for the first time. The optical parameters of BaPd2As2 are also studied in details for the first time. The optical properties compliment the electronic band structure characteristics. Optical constants show significant dependence of the state of polarization of the incident electric field. BaPd2As2 exhibits high reflectance in the infrared and near-visible region and strongly absorbs the ultraviolet radiation. The relevance of the electronic energy density of states and the characteristic phonon frequency to superconductivity in BaPd2As2 is also discussed.

cond-mat.supr-con↗

arXiv2018

Physical properties of niobium based intermetallics (Nb3B; B = Os, Pt, Au): a DFT based ab-initio study

Structural, elastic and electronic band structure properties of A-15 type Nb-based intermetallic compounds Nb3B (B = Os, Pt, Au) have been revisited using first principles calculations based on the density functional theory (DFT). All these show excellent agreement with previous reports. More importantly, electronic bonding, charge density distribution and Fermi surface features have been studied in detail for the first time. Vickers hardness of these compounds is also studied. The Fermi surfaces of Nb3B contain both hole- and electron-like sheets, the features of which change systematically as one move from Os to Au. The electronic charge density distribution implies that Nb3Os, Nb3Pt and Nb3Au have a mixture of ionic and covalent bondings with a substantial metallic contribution. The charge transfer between the atomic species in these compounds has been explained via the Mulliken bond population analysis and the Hirshfeld population analysis. The bonding properties show a good correspondence to the electronic band structure derived electronic density of states (DOS) near the Fermi level. Debye temperature of Nb3B (B = Os, Pt, Au) have been estimated from the elastic constants and show a systematic behavior as a function of the B atomic species. We have discussed implications of the results obtained in this study in details in this paper.

cond-mat.mtrl-sci↗

arXiv2017

Structural, elastic, electronic, and bonding properties of intermetallic Nb3Pt and Nb3Os compounds: a DFT study

Theoretical investigation of structural, elastic, electronic and bonding properties of A-15 Nb-based intermetallic compounds Nb3B (B = Pt, Os) have been performed using first principles calculations based on the density functional theory (DFT). Optimized cell parameters are found to be in good agreement with available experimental and theoretical results. The elastic constants at zero pressure and temperature are calculated and the anisotropic behaviors of the compounds are studied. Both the compounds are mechanically stable and ductile in nature. Other elastic properties such as Pugh's ratio, Cauchy pressure, machinability index are derived for the first time. Nb3Os is expected to have good lubricating properties compared to Nb3Pt. The electronic band structure and energy density of states (DOS) have been studied with and without spin-orbit coupling (SOC). The band structures of both the compounds are spin symmetric. Electronic band structure and DOS reveal that both the compounds are metallic and the conductivity mainly arise from the Nb 4d states. The Fermi surface features have been studied for the first time. The Fermi surfaces of Nb3B contain both hole- and electron-like sheets which change as one replaces Pt with Os. The electronic charge density distribution shows that Nb3Pt and Nb3Os both have a mixture of ionic and covalent bonding. The charge transfer between atomic species in these compounds has been explained by the Mulliken bond population analysis.

cond-mat.mtrl-sci↗

arXiv2017

Elastic, thermodynamic, electronic and optical properties of recently discovered transition metal boride NbRuB superconductors: an ab-initio investigation

The elastic, thermodynamic, electronic, and optical properties of recently discovered and potentially technologically important transition metal boride NbRuB, have been investigated using the density functional formalism. Both generalized gradient approximation (GGA) and local density approximation (LDA) were used for geometrical optimization and for estimation of various elastic moduli and constants. The optical properties of NbRuB have been studied for the first time with different photon polarizations. The frequency (energy) dependences of various optical constants compliment quite well to the essential features of the electronic band structure calculations. Debye temperature of NbRuB has been estimated form the thermodynamical study. All these theoretical estimates have been compared with published results, where available, and discussed in detail. Both electronic band structure and optical conductivity reveal robust metallic characteristics. NbRuB possesses significant elastic and electronic anisotropy. The effects of electronic band structure and Debye temperature on the emergence of superconductivity have also been analyzed.

cond-mat.mtrl-sci↗

arXiv2016

Structural, elastic, and electronic properties of newly discovered Li2PtSi3 superconductor: Effect of transition metals

First-principles calculations within the density functional theory (DFT) with GGA-PBE exchange-correlation scheme have been employed to predict the structural, the elastic and the electronic properties of newly discovered lithium silicide superconductor, Li2PtSi3, for the first time. All the theoretical results are compared with those calculated recently for isostructural Li2IrSi3. The present study sheds light on the effect of replacement of transition metal element Ir with Pt on different mechanical, electronic, and superconducting properties. The effect of spin-orbit coupling on electronic band structure was found to be insignificant for Li2PtSi3. The difference in superconducting transition temperatures of Li2PtSi3 and Li2IrSi3 arises primarily due to the difference in electronic energy density of states at the Fermi level. Somewhat reduced Debye temperature in Li2PtSi3 plays a minor role. We have discussed the implications of the theoretical results in details in this study.

cond-mat.supr-con↗

arXiv2012

Synthesized inverse-perovskites Sc3InX (X = B, C, N): A theoretical investigation

We present first-principles density functional theory (DFT) investigations of mechanical, thermodynamic and optical properties of synthesized inverse-perovskites Sc3InX (X = B, C, N). The elastic constants at zero pressure and temperature are calculated and the anisotropic behavior of the compounds is illustrated. All the three materials are shown to be brittle in nature. The computed Peierls stress, approximately 3 to 5 times larger than of a selection of MAX phases, show that dislocation movement may follow but with much reduced occurrences compared to these MAX phases. The Mulliken bonding population and charge density maps show stronger covalency between Sc and X atoms compared with Sc-Sc bond. The Vickers hardness values of Sc3InX are predicted to be between 3.03 and 3.88 GPa. The Fermi surfaces of Sc3InX contain both hole- and electron-like topology which changes as one replaces B with C or N. The bulk modulus, specific heats, thermal expansion coefficient, and Debye temperature are calculated as a function both temperature and pressure using the quasi-harmonic Debye model with phononic effects. The results so obtained are analysed in comparison to the characteristics of other related compounds. Moreover optical functions are calculated and discussed for the first time. The reflectivity is found to be high in the IR-UV regions up to ~ 10.7 eV (Sc3InB, Sc3InC) and 12.3 eV (Sc3InN), thus showing promise as good coating materials. Keywords: Sc3InX, Mechanical properties; Fermi surface; Quasi-harmonic Debye model; Thermodynamic properties; Optical properties

cond-mat.mtrl-sci↗

arXiv2012

Elastic, thermodynamic, electronic and optical properties of U2Ti

An investigation of U2Ti, a potentially safe and heavy metal-based storage material for radioactive tritium for fusion reactor, has been performed using pseudopotential density functional theory. The analysis of the elastic constants and other moduli calculated for the first time shows large anisotropy on elasticity and brittle behavior. A quasi-harmonic Debye model, which considers the vibrational contribution to the total free energy of the system, has been used to investigate the finite-temperature and finite-pressure thermodynamic properties of U2Ti. The electronic band structure reveals metallic conductivity and the major contribution comes from U-5f states. By analyzing the optical spectra, the origin of the various structures is also explained in terms of the calculated electronic structure. Further the reflectivity spectrum shows that the material is perfect reflector within the energy range 8-12.5 eV. Keywords: Uranium-titanium alloy; First-principles calculations; Quasi-harmonic Debye model; Mechanical properties, Band structure, Optical properties

cond-mat.mtrl-sci↗

arXiv2012

Phase stability, elastic, electronic, thermal and optical properties of Ti3Al1-xSixC2 (0 LE x LE 1): First-principles study

The structural parameters with stability upon Si incorporation and elastic, electronic, thermodynamic and optical properties of Ti3Al1-xSixC2 (0 \leq x \leq 1) are investigated systematically by the plane wave psedudopotential method based on the density functional theory (DFT). The increase of some elastic parameters with increasing Si-content renders the alloys to possess higher compressive and tensile strength. The Vickers hardness value obtained with the help of Mulliken population analysis increases as x is increased from 0 to 1. The solid solutions considered are all metallic with valence and conduction bands, which have a mainly Ti 3d character, crossing the Fermi level. The temperature and pressure dependences of bulk modulus, normalized volume, specific heats, thermal expansion coefficient, and Debye temperature are all obtained through the quasi-harmonic Debye model with phononic effects for T = 0-1000K and P = 0-50GPa. The obtained results are compared with other results where available. Further an analysis of optical functions for two polarization vectors reveals that the reflectivity is high in the visible-ultraviolet region up to ~ 10.5 eV region showing promise as good coating material. Keywords: Ti3Al1-xSixC2; First-principles; Quasi-harmonic Debye model; Mechanical properties; Band structure; Optical properties

cond-mat.mtrl-sci↗