Anisotropy and Superconducting Properties of BaFe₂(As_1-<i>x</i>P_<i>x</i>)₂Films with Various Phosphorus Contents

Abstract

We studied the anisotropy and superconducting properties of BaFe2(As1-xPx)2 films with various phosphorus contents x (=0.19–0.45) fabricated on MgO by pulsed laser deposition. We demonstrated that the x=0.28 film with optimal critical temperature (Tczero=26.5 K) has the lowest anisotropy of upper critical field (γH=1.54), as well as the highest irreversibility field. This is different from the case of cuprate superconductors, and preferable for application. Moreover, the minimum angular dependence of the critical current density for the x=0.28 film at 1 T and 10 K is over 1.0 MA/cm2, indicating that this film could be a promising candidate for in-field application.