AG-LNBA(2)CU(3)O(7-X) (LN=Y, ND, SM, EU, AND YB) SUPERCONDUCTOR COATINGS ON STAINLESS-STEEL

Ag-doped LnBa(2)Cu(3)O(7-x) (Ln = Y, Nd, Sm, Eu, and Yb) films on two kinds of stainless steel substrate were prepared by the method of dire ct deposition and heat treatment. The critical temperatures of the sam ples were evaluated at 91-92 K, independent of silver content and thic kness of the coating layer. The resistance of the samples decreased wi th silver addition. The SEM observation showed a border between the co ating layer and the substrate. The elemental analysis by EPMA revealed that aluminum aggregated in the border. The diffusion of iron ions in the coating layer was hindered by the existence of the border and aff ected by the quantity of aluminum. The width of the border increased w ith increasing heat-treatment time, governed by the diffusion of metal s from the metallic substrate to the coating layer. This fairly agreed with the results of impedance measurements. (C) 1997 Elsevier Science Ltd.