Open AccessStructural, Electronic, Lattice Dynamic, and Elastic Properties of SnTiO3 and PbTiO3 Using Density Functional Theory
Author(s) -
Shiferaw Kuma,
Menberu Mengesha Woldemariam
Publication year - 2019
Publication title -
advances in condensed matter physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.314
H-Index - 26
eISSN - 1687-8124
pISSN - 1687-8108
DOI - 10.1155/2019/3176148
Subject(s) - pseudopotential , bulk modulus , condensed matter physics , density functional theory , lattice constant , phonon , debye model , shear modulus , physics , density of states , tetragonal crystal system , materials science , quantum mechanics , thermodynamics , phase (matter) , diffraction
The structural, electronic, and elastic properties of tetragonal phase of SnTiO 3 and PbTiO 3 are investigated using first principle calculations. The unknown exchange-correlation functional is approximated with generalized gradient approximation (GGA) as implemented in pseudopotential plane wave approach. The convergence test of total energy with respect to energy cutoff and k -point sampling is preformed to ensure the accuracy of the calculations. The structural properties such as equilibrium lattice constant, equilibrium unit cell volume, bulk modulus, and its derivative are in reasonable agreement with the previous experimental and theoretical works. From elastic constants, mechanical parameters such as anisotropy factor A , shear modulus G , bulk modulus B , Young’s modulus E , and Poison’s ratio n are determined by using Voigt–Reuss–Hill average approximation. In addition, Debye temperature and longitudinal and transversal sound velocities are predicted from elastic constants. The electronic band structure and density of states of both compounds are obtained and compared with the available experimental as well as theoretical data. Born effective charge (BEC), phonon dispersion curve, and density of states are computed from functional perturbation theory (DFPT). Lastly, the spontaneous polarization is determined from the modern theory of polarization, and they are in agreement with the previous findings.