Intrinsic pinning by naturally occurring correlated defects in FeSe1−xTex superconductors

Abstract

We study the angular dependence of dissipation in the superconducting state of FeSe and Fe(Se1−x Te x ) through electrical transport measurements, using crystalline intergrown materials. We reveal the key role of the inclusions of the non superconducting magnetic phase Fe1−y (Se1−x Te x ), growing into the Fe(Se1−x Te x ) pure β-phase, in the development of a correlated defect structure. The matching of both atomic structures defines the growth habit of the crystalline material as well as the correlated planar defects orientation.