The under-pressure behaviour of mechanical, electronic and optical properties of calcium titanate and its ground state thermoelectric response

作者：Noor N A; Alay e Abbas S M; Hassan M; Mahmood I; Alahmed Z A; Reshak A H^*

来源：Philosophical Magazine, 2017, 97(22): 1884-1901.

DOI：10.1080/14786435.2017.1320440

• Mechanical properties
• electronic properties
• optical properties
• thermoelectric response

In this study, the elastic, electronic, optical and thermoelectric properties of CaTiO3 perovskite oxidehave been investigated using first-principles calculations. The generalised gradient approximation (GGA) has been employed for evaluating structural and elastic properties, while the modified Becke Johnson functional is used for studying the optical response of this compound. In addition to ground state physical properties, we also investigate the effects of pressure (0, 30, 60, 90 and 120 GPa) on the electronic structure of CaTiO3. The application of pressure from 0 to 90 GPa shows that the indirect band gap (-M) of CaTiO3 increases with increasing pressure and at 120 GPa it spontaneously decreases transforming cubic CaTiO3 to a direct (-) band gap material. The complex dielectric function and some optical parameters are also investigated under the application of pressures. All the calculated optical properties have been found to exhibit a shift to the higher energies with the increase of applied pressure suggesting potential optoelectronic device applications of CaTiO3. The thermoelectric properties of CaTiO3 have been computed at 0 GPa in terms of electrical conductivity, thermal conductivity and Seebeck coefficient.

• 出版日期2017