[19p-234B-1~19] 6.4 薄膜新材料

▲ [19p-234B-3] Phase transformation of octahedral tilted monoclinic SrRuO₃ and tetragonal SrRuO₃ thin film on SrTiO₃ substrate

〇(P)Okkyun SEO¹、Sung Su Lee²、Jaemyung Kim¹、Chulho Song¹、Satoshi Hiroi¹、Yanna Chen¹、Yoshio Katsuya¹、Osami Sakata¹ (1.NIMS/SPring-8、2.GIST)

キーワード：X-ray diffraction, Octahedral tilting

We investigated phase behaviors of octahedral tilted monoclinic and tetragonal SrRuO₃ (SRO) thin film on SrTiO₃ (STO) (001) substrate using the in-situ X-ray diffraction techniques. The monoclinic and tetragonal SRO thin films were epitaxially grown on the STO with a compressive strain. The oxygen octahedral structure of MSRO and TSRO films were octahedral notation of a^-a^-c⁺ and a⁰a⁰c^-, respectively. To investigate the octahedral distortion angle, the phase transformation, and the crystal structure, we measured the 002 Bragg reflection along the substrate normal direction and the 103 Bragg reflection and 2.5 0 1.5 half integer Bragg reflection along the off-specular direction. The phase transformation from the monoclinic to the tetragonal structure occurred at approximately 200 ℃ with second order transition behavior. Conversely, the phase transformation of TSRO thin films did not occur in the range from RT to 250 ℃.