Tạp chí Khoa học Đại học Huế: Khoa học Tự nhiên, T. 126, S. 1B (2017)

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Thermoelectric properties of LaFeO3 system with doped Ti, Co, Cu

Nguyen Thi Thuy

Tóm tắt

Abstract: LaFeO3 system with doped Ti, Co, Cu was manufactured by solid state reaction method, it was sintered at 12500C and 12900C in 10 hours with a heating rate of 30C/min. Using X-ray diffraction and Scanning Electron Microscope (SEM) to examine the structure, it reveals that samples are single-phase and orthogonal-perovskite structure describing by the Pnma space group, the unit cell volume of the samples increases when Ti, Co, Cu are doped to replace ion Fe+3. The size of particle increase while raising the temperature of sintering. Measuring the resistance which depends on temperature between the room temperature and 1000K, it can be seen that when doping Co, Cu with the nominal component La(Fe0,2Co0,2Ti0,6)O3 and La(Fe0,4Cu0,1Ti0,5)O3 , the conductivity of samples increases respectively. Especially, the conductivity of Cu doped sample is higher than two other samples, and reach the highest conductivity at about 9000C, Seebeck coefficient S of La(Fe0.6Ti0.4)O3 can be change from positive to negative at the temperature of around 7000C.