High-Critical-Temperature Sm- and Nd-Based Superconductors Produced by Metal Organic Deposition Using Trifluoroacetates and Pentafluoropropionates

Superconducting films for wire, tape, and microwave filter applications require a high critical temperature ( T c ) and current density ( J c ). Therefore, superconducting systems based on La, Nd, and Sm produced by low-cost non-vacuum metal organic deposition using trifluoroacetates (TFA-MOD) are eagerly awaited. These systems are reported to have excellent T c values of over 94 K, but esterification between trifluoroacetates and methanol leads to low T c values in the TFA-MOD process. Two recent studies on carbon expulsion during calcining and on a quasi-liquid network model during firing suggest new effective chemicals and we successfully prepared Nd- and Sm-based superconductors using pentafluoropropionic acid. The best Nd- and Sm-based films exhibited T c of 93.4 and 93.9 K and J c of 3.4 and 5.1 MA/cm 2 (77 K, 0 T), as measured by the inductive method, respectively. The film thicknesses were 133 and 181 nm, respectively.