Intrinsic pinning by naturally occurring correlated defects in FeSe${}_{\text{1-x}}$Te${}_{\text{x}}$ superconductors

Abstract

We study the angular dependence of the dissipation in the superconducting state of FeSe and Fe(Se${}_{\text{1-x}}$Te${}_{\text{x}}$) through electrical transport measurements, using crystalline intergrown materials. We reveal the key role of the inclusions of the non superconducting magnetic phase Fe${}_{\text{1-y}}$(Se${}_{\text{1-x}}$Te${}_{\text{x}}$), growing into the Fe(Se${}_{\text{1-x}}$Te${}_{\text{x}}$) pure $\beta$-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.