Inserting a thin (t* = 0.5 or 1 nm) layer of the antiferromagnet FeMn into
the "free" Permalloy (Py) layer of a sputtered, current-perpendicular excha
nge-biased spin valve, Nb/FeMn/Py (pinned)/Cu/Py (free)/Nb, is shown to enh
ance A Delta R, the difference in specific resistance between the states wh
ere the magnetizations of the two Py layers are parallel and antiparallel t
o each other. Such an increase is taken as evidence that spin-memory loss (
spin relaxation) due to the FeMn is strong, and that judicious insertion of
a source of spin relaxation into a multilayer with high specific resistanc
e contacts can enhance A Delta R, the numerator of the magnetoresistance. (
C) 2000 American Institute of Physics. [S0021-8979(00)57308-3].