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In the present density functional studies, structural, mechanical and magneto-electronic properties of CaTaO 3, SrTaO 3 and BaTaO 3 perovskites have been investigated. The calculated structural parameters by DFT and analytical methods are found consistent with the experiments. The analytically calculated tolerance factors of these compounds as well as their mechanical properties show that they are stable in the cubic phase. Furthermore elastic properties show that these materials are ductile in nature and confirm that BaTaO 3 is harder than the rest compounds. The calculated spin dependent magneto-electronic properties reveal the paramagnetic metallic nature of these compounds. The electrical conductivity curve demonstrates significant conductivity above room temperature. On the basis of the presented properties it is expected that these compounds could be efficient electrode materials and need experimental investigations. [ABSTRACT FROM AUTHOR]

Structural, electronic, optical and magnetic properties of titanium based perovskites La 2 MTiO 6 (M = Co, Ni, Cu and Zn) are investigated in monoclinic phase with space group (P2 1 /n) in the domain of density functional theory (DFT). The generalized gradient approximation plus Hubbard potential (GGA + U) is utilized to study these high correlated electrons systems. Structural parameters are found in closed agreement with experiments. Cohesive energy reveals that La 2 CoTiO 6 is more stable among these compounds. The electronic properties show the semiconductor behavior of these compounds with band gap varies from 1.02 to 2.3 eV. Optical properties demonstrate that all these compounds are potential candidates for optoelectronic devices. The electrical resistivity which increases in a sequence from Co to Zn also confirms the semiconductor nature of these compounds. The magnetic susceptibility curves show that La 2 CoTiO 6 , La 2 NiTiO 6 and La 2 CuTiO 6 are antiferromagnetic whereas La 2 ZnTiO 6 is a paramagnetic material. Based on the semiconductor antiferromagnetic nature of La 2 CoTiO 6 , La 2 NiTiO 6 and La 2 CuTiO 6 it is expected that these compounds could be used as pinning layers in spin valves and storage devices. • La 2 MTiO 6 (M = Co, Ni, Cu and Zn) perovskites are semiconductors with band gaps ranges from 1.2 to 2.3 eV. • These compounds are optically active in the broad range electromagnetic spectrum. • Electrical resistivity increases in a sequence from Co to Zn and confirms the semiconductor nature of these compounds. • Perovskites La 2 CoTiO 6 , La 2 NiTiO 6 and La 2 CuTiO 6 are antiferromagnetic whereas La 2 ZnTiO 6 is a paramagnetic material. [ABSTRACT FROM AUTHOR]

AMn 3 V 4 O 12 (A = Ca, Ce and Sm) quaternary perovskites are studied in the domain of density functional theory using various potentials. Generalized gradient approximation along with Hubbard U and hybrid density functional schemes are found effective tools for the treatment of these compounds. Changing of A-site cation, affects the physical properties due to the valence distributions Ca+2Mn+2 3 V+4 4 O 12, Ce+3Mn+2 3 V+3.75 4 O 12 and Sm+3Mn+2 3 V+3.75 4 O 12 respectively. Cohesive energy and enthalpy show that these compounds are thermodynamically stable. Electronic and electrical properties reveal the semi-metallic nature of these compounds. It is observed that in these compounds Aʹ-site (Mn) 3d electrons are localized and responsible for the magnetic properties whereas B-site (V) 3d electrons are delocalized, contributed in the electronic behavior. The elastic properties also confirm the stability and demonstrate that these compounds are ductile in nature. DFT as well as post−DFT treatments verify the anti-ferromagnetic nature of these compounds with the dominant Mn+2―O−2―Mn+2 super exchange interactions. • Cohesive energy and enthalpy show that these perovskites are thermodynamically stable. • Elastic properties confirm the stability and demonstrate that these compounds are ductile. • Electronic band profiles and electrical properties reveal the semi-metallic nature of the compounds. • These compounds are anti-ferromagnetic with the dominant Mn+2―O−2―Mn+2 super exchange interactions. [ABSTRACT FROM AUTHOR]