[15p-4A-1~17] 11.2 Thin and thick superconducting films, coated conductors and film crystal growth

[15p-4A-16] Compressive strain of FeSe_1-xTe_x films on CaF₂ substrates

〇Ataru Ichinose¹, Ichiro Tsukada¹, Fuyuki Nabeshima², Yoshinori Imai², Atsutaka Maeda² (1.CRIEPI, 2.Univ. of Tokyo)

Keywords:Fe-based 11 superconductor,microstructure,CaF2

The critical temperature of FeSe_1-xTe_x films fabricated on CaF₂ substrates is higher than that of the bulk samples. This phenomenon is explained by the changes of lattice lengths of superconducting films. That is, the a-axis length of superconducting films shrinks than that of bulk samples, while the c-axis length of superconducting films expands than that of bulk samples. However, the change in the axial length of the superconducting film on the CaF₂ substrate cannot be explained by simple epitaxial strain. Therefore we investigate the vicinity of the interface between superconducting films and substrates using a transmission electron microscope.