[21p-B204-1~17] 6.3 Oxide electronics

[21p-B204-16] Electrochemical Redox Treatment and Heat-Electron Transport Properties of SrCoO_x-SrFeO_x Solid Solution Films

〇(D)Zhiping Bian¹, Qian Yang², Mitsuki Yoshimura³, Hai Jun Cho⁴, Hiromichi Ohta⁴ (1.IST-Hokudai, 2.Jiangsu Univ., 3.Eng.-Hokudai, 4.RIES-Hokudai)

Keywords:thermal transistor

In order to improve the performance of the thermal transistor, detailed mechanism of the thermal conductivity change needs to be clarified. In this study, we focused on the changes in the electron transport and crystal structure of SrCoO_x-SrFeO_x solid solutions (SCFOss hereafter) because the crystal structure of SrFeO₂ is an infinite layer different from that of SrCoO₂ (defect perovskite).
Out-of-plane XRD patterns of the oxidized SCFOss films indicated that perovskite structured SrCo_1−xFe_xO₃ solid solutions were obtained. The electrical resistivity (ρ) of the SFCOss increased gradually with x. The thermopower (S) was negative in all cases. Absolute value of S gradually increased with x. These results may reflect gradual change in the electronic states with x. Then, we measured the cross-plane thermal conductivity of the films x = 0 and 1 and found the x = 0 film (~3.8 W m⁻¹ K⁻¹) shows ~1 W m⁻¹ K⁻¹ higher thermal conductivity than x = 1 film (~2.9 W m⁻¹ K⁻¹). Using the in-plane electrical conductivity, we calculated the electron thermal conductivity and found that κ_ele of the x = 0 film (~1 W m⁻¹ K⁻¹) is ~1 W m⁻¹ K⁻¹ higher than that of x = 1 film (≈ 0). We would like to discuss on the thermal conductivity of both oxidized and reduced films at the conference.