低酸素圧下で合成したエピタキシャルLa_0.5Sr_0.5CoO₃(LSCO) 薄膜の電気特性

抄録

A new range of oxygen pressure for the preparation of La_0.5Sr_0.5CoO₃(LSCO) thin films was proposed. In this work, heteroepitaxial LSCO thin films were prepared on CeO₂/YSZ/Si(001) substrates in 7.3×10^-2PaO₂ atmosphere, while LSCO thin films have been prepared in a higher oxygen pressure around 1.3-4.0×10¹Pa in the literature. The film has smooth morphology and high crystallinity as well as low resistivity (2×10^-3Ωcm). The reason may be related to the long mean free path (MFP) in the depositied LSCO thin film. The film showed semiconductive property due to oxygen vacancies. By the post annealing in O₂, the lattice parameter of LSCO thin film was increased and the resistivity was lowered.