LARGE MAGNETORESISTANCE WITH LOW SATURATION FIELDS IN MAGNETIC MAGNETIC SUPERLATTICES

Ni/Co multilayers grown by molecular beam epitaxy are found to exhibit a magnetoresistance DELTAR/R at liquid helium temperature as large as 8.2%, with saturation fields DELTAH almost-equal-to 22 Oe and a sensi tivity (DELTAR/R)/(2DELTAH) almost-equal-to 0.19% Oe-1. The highest ro om temperature sensitivity obtained to date in this system is 0.18% Oe -1 and at 4.2 K is 0.29% Oe-1. This demonstrates that high values of t he sensitivity can be achieved in multilayers in which both components are ferromagnetic. The magnetoresistance and saturation field can be tuned by the superlattice and growth parameters.