High Tc superconducting HoBa/sub 2/(Cu/sub 1-x/Fe/sub x/)/sub 3/ O/sub 7-y/

The dc magnetization measurements (x = 0 or 0.05) show that the onset T/sub c/ is 90/degree/K for x = 0 (orthorhombic) and 48/degree/K for x = 0.05 (tetragonal). The Fe valence state is probably predominately Fe(III), from the /sup 57/Fe Moessbauer spectra. 2 figs. (DLC)