Large positive magnetoresistance (LPMR) effects have been measured at
temperatures T < 100 K in epitaxial Cr/Ag/Cr trilayers grown by molecu
lar beam epitaxy. Compared to single Ag films, the magnetoresistance a
t 4.2 K is enhanced by nearly two orders of magnitude reaching values
up to 120% in a field of 8 Tesla. This behavior is related to a drasti
c modification of the electron scattering at the Ag interfaces due to
the presence of the buffer and cap Cr layers. The LPMR curves measured
at different temperatures demonstrate a scaling behavior typical for
electron transport in two-dimensional systems. The magnitude of the LP
MR is a function of temperature and residual resistance ratio and is i
nfluenced by the direction of the applied magnetic field. (C) 1997 Ame
rican Institute of Physics.