The transport properties of YBa2Cu3O7-delta/permalloy interfaces as a
function of temperature and small magnetic fields are presented. High
quality (001) and (100) oriented YBa2Cu3O7-delta (YBCO) thin films are
prepared by the off-axis sputtering technique. Permalloy (Ni0.8Fe0.2)
films are then deposited on top of the YBCO films, and patterned in o
rder to obtain sub-millimeter contacts. The interface resistances in t
he normal and superconducting state of the YBCO are measured as a func
tion of an applied magnetic field. The results are discussed in the fr
amework of electron spin transport across the interface and spin diffu
sion in the bulk of the superconductor.