PERPENDICULAR RESISTANCE OF CO CU MULTILAYERS PREPARED BY MOLECULAR-BEAM EPITAXY/

The magnetoresistance (MR) of layered metal systems with the current i n a direction perpendicular to the plane of the layers (CPP) is studie d. The technique for measuring the resulting very small resistances ut ilises a SQUID to act as a high-precision current comparator. The samp les are Co/Cu multilayers grown by molecular beam epitaxy (MBE) in ult rahigh vacuum (UHV). Perpendicular resistance measurements are reporte d for Nb/Cu/X/Cu/Nb where X is the Co/Cu multilayer. The Co is fixed a t a nominal value of 1.5 nm while the Cu is varied between 1 and 5 nm. These measurements show large oscillations in the CPP-MR as the Cu th ickness is increased. A comparison is made between MBE and sputtered s amples.