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In the present paper, the electronic, structural, thermodynamic, and elastic properties of cubic $PbGeO_{3}$ perovskite oxide are presented and computed using the WIEN2K code. The structural properties have been evaluated and they are in good agreement with the theoretical and experimental data. A phonon dispersion is made and it reveals that the cubic $PbGeO_{3}$ perovskite is dynamically stable. In addition, the electronic properties of $PbGeO_{3}$ shows an opening gap energy, meaning a semiconductor behavior with an indirect band gap equal to $1.67 eV$. Moreover, the obtained elastic constants of cubic $PbGeO_{3}$ satisfy Born's mechanical stability criteria, and this indicates that our compound behaves as a stable ductile material. The temperature-pressure effects on thermodynamic parameters are investigated using the Gibbs$2$ package. Finally, based on the obtained results about the cubic $PbGeO_{3}$ perovskite properties, we assume that this compound will have potential applications., Comment: 17 pages, 9 figures

The electronic, elastic, structural, thermoelectric and optical parameters of the Pb-based cubic perovskites $PbREO_3\; (RE=Ce,\; Gd,\; Nd)$ were calculated using the WIEN2k Package. The mechanical optimization and structural stabilities were evaluated. The found results are in full agreement with the experimental ones. The obtained elastic results show that these perovskites behave as stable ductile materials, and their higher $Y$ value gives them a rigid structures. The $PbCeO_3$ presents n-type semiconductor while $PbREO_3\; (RE= Gd,\; Nd)$ exhibit p-type semi-conductor with gap energies of $2.60\;eV$, $1.02\;eV$ and $1.55\;eV$, respectively. The optical properties show that $PbREO_3\; (RE=Ce,\; Gd,\; Nd)$ have significant absorption in the visible light region with low reflectivity. The thermoelectric properties present a desired electrical performance at room temperature for all materials. For these generation of materials the effect of RE on Pb-based cubic perovskite oxides can be exploited in manufacturing of thermoelectric, mechanic and optoelectronic devices., Comment: 23 pages, 21 figures

Various physical properties (electronic, optical and thermoelectric) of cubic perovskite oxides $SrXO_3\; (X=Sc,\; Ge,\; Si)$ are investigated by using the density functional theory (DFT) within Wien2k code. This code is based on different approximations such as generalized gradient approximation GGA, PBEsol, LDA, WC and the modified Becke-Johnson exchange potentials (mBJ, nmBJ and unmBJ). Structural properties and the optimization have been calculated using PBEsol functional which showed a significant results that are in good agreement with the experimental ones. The results for physical properties such as electronic, thermoelectric and optical are analyzed in detail by using the nmBJ approximation. The obtained results present an opening gap for $SrSiO_3$, $SrGeO_3$ and a metallic behavior for $SrScO_3$. An average of transmittance which is about $94\%$ to $97\%$ was observed in the range of visible light. The increase of electrical conductivity with temperature confirms the effect of thermal agitation on the concentration of charges carriers using BolzTrap Package. Lastly a phonon dispersion was made and show that for $X=\; Ge$ and $Si$, the structure is relatively stable while $SrScO_3$ is dynamically unstable. These results prove the ability that these materials can be exploited in many applications and manufacturing of optoelectronics for Sensors., Comment: 22 pages, 16 figures