[24p-12G-1~14] 6.3 Oxide electronics

2:15 PM - 2:30 PM JST(5:15 AM - 5:30 AM UTC)

[24p-12G-4] Room-Temperature Current-Induced Transition in Ca₂RuO₄ Thin Films Grown Based on Interstitial Cation Diffusion in the Ruddlesden–Popper Structure

〇Atsushi Tsurumaki-Fukuchi¹, Takayoshi Katase², Toshio Kamiya² (1.Faculty of IST, Hokkaido Univ., 2.MDXES, Tokyo Tech.)

Keywords:

epitaxial growth,Ruddlesden-Popper oxide,metal-insulator transition

In epitaxial thin films of Ca₂RuO₄/LaAlO₃ (001) grown by the solid-phase epitaxy using an external cation source (fine polycrystalline powder of Ca₂RuO₄), the occurrence of an unconventional, interstitial type of cation diffusion in the n = 1 Ruddlesden–Popper structure was suggested for the Ru and La ions through high-resolution transmission electron microscopy analyses for the thin films. The observations of this study indicated that the interstitial cation diffusion from the external powder souses causes effective compensation of the Ru vacancies in the thin films without largely reconstructing the host Ca₂RuO₄ structure and enable high-quality epitaxial film growth of Ca₂RuO₄ with reduced Ru-deficiency formation. Moreover, in the Ca₂RuO₄/LaAlO₃ (001) thin films after the Ru-deficiency compensation, room-temperature observations of the current-induced metal–insulator quantum phase transition was demonstrated through electrical transport measurements.