THERMOELECTRIC PROPERTIES OF LaFeO3 SYSTEM DOPED WITH Ti, Co, AND Cu

Abstract

A LaFeO₃ system doped with Ti, Co, and Cu was manufactured using the solid-state reaction method. It was sintered at 1250 °C and 1290 °C for 10 hours with a heating rate of 3 °C/min. The materials have a single-phase and orthogonal-perovskite structure which is characteristic of the Pnma space group. The unit cell volume of the materials increases when Ti, Co, Cu replace Fe⁺³. The size of the particles increases while raising the sintering temperature. The resistance depends on the temperatures between the room temperature and 1000 K. Doping Co, Cu with the nominal component La(Fe_0.2Co_0.2Ti_0.6)O₃ and La(Fe_0.4Cu_0.1Ti_0.5)O₃ increases the conductivity of materials. The Seebeck coefficient of La(Fe_0.6Ti_0.4)O₃ changes from a positive value to a negative value at around 700 °C.