Growth of High-Performance 4-5μm Thick Film REBCO Tapes Doped With Hafnium Using Advanced MOCVD

Advanced metal organic chemical vapor deposition technique (A-MOCVD) was used to grow 4-5 μm thick REBa
₂
Cu
₃
O
_7-δ
(REBCO, RE = rare earth) films, doped with 5% and 15% Hf. Thick REBCO films doped with 5% Hf exhibit self-field critical current density (J
_c
) over 1.8 MA/cm
²
at 77 K and 3 MA/cm
²
at 65 K, 1.5 T. Increasing the Hf content to 15% resulted in J
_c
above 9 MA/cm
²
at 20 K, 9 T. The effect of (Ba+Hf)/Cu content in Hf-added (5 and 15 mol.%) REBCO films on the critical current density at 77 K, 0 T, c-axis lattice parameter and out-of- plane texture has been studied. In addition to growth of thick film REBCO tapes with superior performance, the A-MOCVD reactor has been used to quadruple the precursor-to-film conversion efficiency above 45%. This achievement has a first order impact in lowering the cost of REBCO tapes made by A-MOCVD.