[15p-F206-1~14] 22.1 Joint Session M

[15p-F206-10] Characteristics of thermal conductivity for titanium oxides with periodic stacking faults

〇Shunta Harada¹, Katsushi Tanaka², Haruyuki Inui³ (1.IMaSS Nagoya Univ., 2.Kobe Univ., 3.Kyoto Univ.)

Keywords:thermoelectric, oxides, superlattice

Most of existing thermoelectric materials are composed of highly toxic and rare elements such as Bi and Te. Therefore, development of environmentally freindly materials with high thermoelectric performance is desired.Ti_nO_2n-1 which is the reduced phase of TiO₂ has a superlattice structure (shear structure) including periodic stacking faults in the mother lattice of a rutile structure. The maximum dimensionless figure of merit ZT = 0.14 has been reported reported so far.In this study, we investigated the correlation between the periodic stacking faults which varies with the amount of oxygen and thermal conductivity. As the stacking fault density increases, the thermal conductivity decreases, which indicates that stacking faults introduced at high density became scattering sources of phonons.