Computational mining of the pressure effect on thermodynamic and thermoelectric properties of cubic Ca₂Si

¹ Multiscale Computational Materials Facility, and Key Laboratory of Eco-materials Advanced Technology, College of Materials Science and Engineering, Fuzhou University - Fuzhou 350108, PRC
² School of Materials Science and Engineering, and Center for Integrated Computational Materials Engineering, International Research Institute for Multidisciplinary Science, Beihang University - 100191 Beijing, PRC

^(a) bssa@fzu.edu.cn (corresponding author)
^(b) zmsun@buaa.edu.cn (corresponding author)

Received: 30 June 2018
Accepted: 21 September 2018

Abstract

Adjusting external pressure has been emerging as one of the most powerful method to unravel the physical and chemical origin of the materials. In this work, we have investigated the pressure effect on thermodynamic and thermoelectric properties of the cubic phase Ca₂Si systematically based on density functional theory within quasi-harmonic approximation and semi-classical Boltzmann transport theory. Our results not only shed light on the origin of the stability of cubic Ca₂Si at all the pressures but also provide thermodynamic and thermoelectric maps for cubic Ca₂Si under various external pressures. By combining the Seebeck coefficient decreasing and electronic conductivity increasing, the pressure independent power factor of cubic Ca₂Si have been highlighted as well. We believe that our findings will facilitate the pressure related applications of Ca₂Si in extensive fields.