Regular Article

Effect of Ca and/or Mn substitution on thermoelectric properties of SrTiO₃

Department of Physics, Sri Manakula Vinayagar Engineering College, Puducherry, India

^* e-mail: d.mohanradheep@gmail.com

Received: 18 September 2020
Received in final form: 26 December 2020
Accepted: 28 January 2021
Published online: 22 March 2021

Abstract

Thermoelectric properties have been investigated for Sr_0.5Ca_0.5Ti_1-xMn_xO₃ (x = 0.25, 0.5, 0.75) and Sr_0.75Ca_0.25Ti_0.75Mn_0.25O₃ perovskite polycrystalline samples synthesized by solid-state reaction method. Following physical properties such as thermal conductivity, electrical resistivity, Seebeck coefficient, power factor and figure of merit (ZT) were measured. The substitution of Ca²⁺ in Sr²⁺ site or/and mixed valence Mn in Ti site creates appreciable enhancement in the thermoelectric properties with an increase of ZT from 0.5 to 0.69 at room temperature. The origin for the enrichment of ZT of the investigated samples around room temperature is due to substitution induced distortion in the cubic lattice.