Influence of Ar background gas pressure on composition and crystal orientation in PLD-Fe(Se1-xTex) thin films

摘要

Fe(Se_(1-x)Te_x) thin films on (1 0 0) SrTiO_3 were fabricated by a pulsed laser deposition method, and their crystal orientation, compositional shifts and superconducting properties were characterized by X-ray diffraction, scanning electron microscope combined with energy dispersive X-ray spectroscopy, etc. Compositional shift is one of the major problems during the fabrication of Fe(Se_(1-x)Te_x) films due to its containing high volatile elements such as Se and Te. The compositional shifts were found dependent on the Ar background gas pressure (P_(Ar)), which was suppressed by the increase of P_(Ar). In addition, it was revealed that the temperature window for the crystallization of the films was shifted to higher temperature region and wider temperature range with the increase of P_(Ar).