[16p-D411-1~13] 9.4 Thermoelectric conversion

[16p-D411-8] Fabrication and thermoelectrical properties of orientated bulk [Ca₂(Co_0.65Cu_0.35)₂O₄]_0.63CoO₂ samples

〇Yoshimi Shimizu¹, Kei Hayashi¹, Yuzuru Miyazaki¹ (1.Tohoku Univ.)

Keywords:Thermoelectric Materials, Layered cobalt oxide

Co-121 has a crystal structure that consists of an alternate stacking of a CdI2-type CoO₂ conduction sheet and a three-layered rock salt (RS)-type Ca₂CoO₃ block layer (BL) parallel to the c-axis. It has excellent thermoelectric (TE) properties above 800K. However, Co-121 has high electrical resistivity on a polycrystalline sample because of the difficulty in conducting electricity in the c-axis. (Co, Cu)-221 has a four-layered RS-type BL and has lower electrical resistivity than Co-121 in the polycrystalline sample above 450K.
In this work, we fabricate an orientated bulk (Co, Cu)-221 samples and compare them with the TE properties of Co-121.