Epitaxial growth of hexagonal tungsten bronze CsXWO3 films in superconducting phase region exceeding bulk limit

摘要

We report epitaxial synthesis of superconducting CsXWO3 (x = 0.11, 0.20, and 0.31) films on Y-stabilized ZrO2 (111) substrates. The hexagonal crystal structure was verified not only for the composition within the stable region of the bulk (x = 0.20 and 0.31), but also for the out-of-range composition (x = 0.11). The onset of the superconducting transition was recorded at 5.8 K for x = 0.11. We found a strong correlation between the superconducting transition temperature (TC) and the c-axis length, irrespective of the Cs content. These results indicated that the hidden superconducting phase region of hexagonal tungsten bronze is accessible using epitaxial synthesis of lightly doped films. (C) 2016 The Japan Society of Applied Physics