[9a-Z05-1~8] 6.4 Thin films and New materials

[9a-Z05-7] Strain-induced non-volatile modification of transition temperature in VO₂ thin films

〇Joe Sakai¹, Masashi Kuwahara², Motoki Takada³, Kunio Okimura³, Yoichi Uehara⁴ (1.ICN2, 2.AIST, 3.Tokai Univ., 4.RIEC Tohoku Univ.)

Keywords:vanadium oxide, chalcogenide, phase transition temperature

We evaluated the phase transition temperature (T_tr) in VO₂ layers in samples consisting of Ge₂Sb₂Te₅ (GST) /VO₂ bilayered films on sapphire substrates, at both steps in which the GST layer is amorphous and crystalline. Temperature dependence of optical reflection intensity and electrical resistance were adopted for the evaluation. The result revealed that the crystallization process of the GST layer was accompanied by lowering of T_tr in the VO₂ layer. The non-volatile modification of T_tr was probably induced through strain in the VO₂ layer, which originated in volume shrinkage of the GST layer at its amorphous – crystalline phase change.