  From both theory and experiment, scattering of minority electrons is expected
to be weaker than scattering of majority electrons in both dilute Fe(Cr) alloys
and at Fe(Cr)/Cr interfaces. We show that Fe(Cr)/Cr/Fe(Cr) trilayer nanopillars
display a normal magnetoresistance--i.e., largest resistance at low magnetic
fields and smallest at high fields, but an inverted current-driven
switching--i.e., positive current flowing from the fixed to the reversing layer
switches the trilayer from higher to lower resistance, and negative current
switches it from lower to higher.
