First-principles investigation of the equation of state and elastic properties of perovskite-type SrW(O,N)3 under hydrostatic pressures up to 139 GPa
1 Department of Physical Chemistry, Shahrood Branch, Islamic Azad University, Shahrood, Iran
2 Department of Natural and Mathematic Sciences, Turin Polytechnic University in Tashkent, Kichik Halqa Yo’li 17, 100095 Tashkent, Uzbekistan
Received: 12 December 2016
Published online: 13 March 2017
Pressure dependence of the structural and elastic properties of perovskite-type cubic SrWO2.05N0.95 was studied using firstprinciples density functional theory (DFT) utilizing the plane wave pseudopotential and the exchange-correlation functionals within the generalized gradient approximation. The estimated bulk modulus and its pressure derivative values from the P − V data fitted to the third-order Birch-Murnaghan equation of state were close to the data obtained from the independent elastic constants. Based on the generalized Born stability criteria, SrWO2.05N0.95 is mechanically stable up to 139 GPa. The influence of hydrostatic pressure (0 to 139 GPa) on the bulk modulus, shear modulus, Young’s modulus, Pugh’s modulus ratio, Poisson’s ratio, Vickers hardness, sound velocities, Debye temperature, Debye-Grüneisen parameter, minimum thermal conductivity and elastic anisotropy of SrWO2.05N0.95 was particularly studied in detail. It was found that SrWO2.05N0.95 is a ductile and hard solid with large bulk, shear and Young’s modulus and displays an extraordinary low thermal conductivity. Since there are not any experimental or theoretical data available for comparison the results of the present study have revealed an important fundamental information about the elastic properties of perovskite-type cubic SrWO2.05N0.95 for future experimental studies.
Key words: Computational Methods
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2017