Anisotropic Behaviors in (${\text{Li}}_{1-x} {\text{Fe}}_{x}$ ) OHFeSe Superconducting Single Crystals

Abstract

( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{Li}}_{1-x} {\text{Fe}}_{x}$</tex-math></inline-formula> )OHFeSe single crystals have been synthesized with a hydrothermal ion-exchange growth method. The physical properties are characterized by electrical and magnetic measurements. ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text{Li}}_{1-x} {\text{Fe}}_{x}$</tex-math></inline-formula> )OHFeSe undergoes a resistive superconducting (SC) transition in zero field at <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> (onset) = 41.4 K. The broadening effect of the magnetic (resistive) SC transition width is anisotropic and is larger for magnetic fields parallel to the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</i> -axis than for fields parallel to the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ab</i> -plane. The layered crystal structure plays an important role in the anisotropic broadening. The tuning effects of magnetic field on the anisotropies are observed, which shed light on the SC mechanism and the emerging device applications.