[12a-N106-1~9] 22.1 Joint Session M "Phonon Engineering"

△ [12a-N106-6] Reduction of Thermal Conductivity of Metal-Insulator Superlattice using Non-Equilibrium Electron-Phonon Heat Transport near the Interface

〇(M2)Kyoungjung Kim¹, Yosuke Kurosaki², Naoto Fukatani², Shin Yabuuchi², Yusuke Ira¹, Shao Cheng¹, Jun Hayakawa², Junichiro Shiomi¹ (1.Dept. of Mech. Eng., Tokyo Univ., 2.R&D Group, Hitachi Ltd.)

Keywords:Metal/Insulator superlattice, Electron-Phonon coupling, Nano-scale heat transport

The thermal conductivity is measured using Time-domain thermoreflectance method for superlattice samples composed of insulator (MgO) and metals (AuSi, Ta, CoFeB) with different electron-phonon coupling strength. As a result, the thermal conductivity of the superlattice decrease as the unit layer thickness of the superlattice become thinner for all three types of superlattice samples. The difference in thermal conductivity between dissimilar metal superlattice samples having the same unit layer thickness is considered to be due to the change in non-equilibrium heat transport between electrons and phonons near the interface.