Effect of variation of metal and non‐metal elements on various properties of rare‐earth‐based inverse perovskites Gd₃XY (X = Ga, In and Y = B, N)

Abstract

Ferromagnetic rare-earth-based inverse perovskites Gd 3 AlX (X = B, N) are studied using hybrid functionals in the framework of density functional theory. Different exchange correlation potentials are employed to analyze the structural parameters and geometry of the materials. The spin polarization and band structure explain the metallic behavior of these materials with high values of magnetic moment. The calculated elastic constants specify all materials are ordered perovskite compounds, among which Gd 3 GaB, Gd 3 GaN, Gd 3 InN are brittle in nature while as Gd 3 InB is ductile in nature. The quasi-harmonic Debye model was used to predict the thermodynamic properties of the material. The analysis of thermoelectric properties viz. Seebeck coefficient, electronic and thermal conductivities at higher temperature has been carried out. To check the optoelectronic response of the material various optical properties have been calculated up to 14 eV photon energy range. The competent thermoelectric and optoelectronic properties with high value of magnetic moment and ductile character suggests the application in thermoelectric and electro-optic devices. K E Y W O R D S ductile, electronic structure, ferromagnetic, magnetic moment, optical absorption, Seebeck coefficient, specific heat, thermoelectric 1 | INTRODUCTIONThe increasing energy demands and environmental problem is a great challenge faced by the scientific community. Due to overuse of fossil fuels, it is necessary to find an alternate way of generation of electric energy and reduce the consumption of these fuels. Thermoelectric materials are promising candidates for transformation of waste heat into functional electric energy. So, thermoelectric is a promising technology for reducing the use of fossil fuels and hence provide a solution for energy crisis as well as environmental problems. [1][2][3] The exploitation of thermoelectric devices is limited due to their low performance, which is generally given by figure of merit ZT = S 2 σT κe + κ l ð Þ where each letter has its usual meaning. [4][5][6][7][8] Thus, the performance of thermoelectric materials can be improved by increasing the power factor (S 2 σ) and by controlling the thermal conductivity of a material. Various members of chalcogenides, skutterudites, clathrates, Heusler alloys have a greater potential towards the thermoelectric applications. [5,9] Among all thermoelectric materials perovskite materials have attracted many researchers due to their eco-friendly, high temperature stability, nontoxicity and environment friendly. [10][11][12] Perovskite oxides show astonishing properties that makes them important for various applications. [13] Finding new perovskites and tailoring of these materials for various properties have remained an active subject of research. The inverse perovskites, crystallizing in the antiperovskite type of structure, with the reverse occupancy of cations and anions, A 3 XY (A = metal; X = metalloid; Y = B, C, N, O), exhibit a growing variety of interesting physical properties s...

Inspecting the Thermoelectric Response and Mechanical Stability of Novel Cobalt‐Based Heusler Alloys: A DFT Insight

“…The mechanical stability delivers enhanced clarifications of the materials to comprehend the fundamental characteristics like elasticity, phase transition, interatomic forces, mechanical features, etc. [ 32–36 ] In condensed matter physics, elasticity is the vital and energetic feature of a compound, where the basic elastic properties of a compound are very crucial as they decide the necessary information to fulfill the other numerous mechanical criteria for the stability of an alloy. The necessity requirement of the cubic elastic constants is illustrated usually by the Born–Haung hints to subsequent constraints as [ 37–41 ] …”