A high critical current density MOCVD coated conductor with strong vortex pinningcenters suitable for very high field use

Abstract

We have made extensive low temperature and high field evaluations of a recent2.1 µm thick coated conductor (CC) grown by metal–organic chemical vapor deposition (MOCVD)with a view to its use for high field magnet applications, for which its very strong Hastelloysubstrate makes it very suitable. This conductor contains dense three-dimensional(Y,Sm)2O3 nanoprecipitates, which are self-aligned in planes tilted∼7° from the tape plane. Very strong vortex pinning is evidenced by high critical current densityJc valuesof ∼3.1 MA cm−2 at77 K and ∼43 MA cm−2 at 4.2 K, and by a strongly enhanced irreversibility fieldHirr, whichreaches that of Nb3Sn (∼28 T at 1.5 K) at 60 K, even in the inferior direction of axis. At 4.2 K, Jc valuesare ∼15% of the depairingcurrent density Jd, much the highest of any superconductor suitable for magnet construction.