[21a-W323-1~10] 9.4 Thermoelectric conversion

△ [21a-W323-3] Microscopic Thermal Transport and its Suppression Mechanism in Layered Cobalt Oxides

〇(D)Susumu Fujii¹, Masato Yoshiya^1,2 (1.Osaka Univ., 2.JFCC)

Keywords:Thermal Conduction,Layered Oxides,Perturbed Molecular Dynamics

In order to clarify the atomistic mechanism of phonon thermal conduction in layered cobaltites, we have conducted systematic calculations of phonon thermal conductivity using perturbed molecular dynamics method. As a result, it is found that CoO₂ layers, which are common in layered cobaltites, transport most of heat, and that the thermal conductivity of CoO₂ layers greatly depends on types of the neighboring layers. Further, through various evaluation of atomic vibration, it was also clarified that an anharmonic vibrational characteristics in the neighboring layers trigger the suppression of phonon thermal conductivity. In addition, we evaluated the contribution of each wave to total thermal conduction quantitatively, for better understanding of the suppression mechanism of thermal conduction.