Temperature and Magnetic Field Dependence of Critical Current Density of YBCO With Varying Flux Pinning Additions

The critical current density (J c ) of YBa 2 Cu 3 O 7-z films doped with varying flux pinning nanoparticle additions was systematically studied, for applied magnetic fields of H = 0-9 T and operation temperatures T = 20-77 K. Films were prepared with pulsed laser deposition by (M/YBCO) N multilayer or (YBCO) 1-x M x single-target methods, for different M phases including Y 2 O 3 , Y 2 BaCuO 5 (Y211) green-phase, and BaZrO 3 . Very significant differences of J c (H//c,20-77 K) were measured for optimized M phase additions, that are difficult to model or predict at present. Multilayer films with Y211 and Y 2 O 3 nanoparticle additions had the highest J c (20-77 K) for H c (H) for H > 4 T and 65-77 K, however not for T c (H,T) properties were measured for (BZO/YBCO) N multilayer films when compared to YBCO and other doped films; J c (H) was almost the same as YBCO at 77 K, however at 30 K J c (H > 2 T) had the strongest properties increasing 70% compared to YBCO+nanoaddition films and increasing 400% compared to YBCO.