Deposition of YBCO and NBCO films on areas of 9 inches in diameter

Abstract

High quality YBa/sub 2/Cu/sub 3/O/sub 7/ thin films can be grown by reactive thermal co-evaporation. Combined with a rotating disk heater this method allows to fabricate even double sided homogeneous films on substrate areas up to 9" diameter. A scanning inductive j/sub c/ probe is used to monitor the homogeneity of critical current densities of typically >2 MA/cm/sup 2/. Surface resistance values are found to be below 500 /spl mu//spl Omega/ at 10 GHz. On biaxially aligned buffer layers on polycrystalline substrates j/sub c/ values of 1.3 MA/cm/sup 2/ are achieved as well. The properties of Nd/sub 1-x/Ba/sub 2+x/Cu/sub 3/O/sub 7/ films grown with the same system are presented and evaluated.