PERPENDICULAR GIANT MAGNETORESISTANCE OF MICROSTRUCTURES IN FE-CR ANDCO-CU MULTILAYERS

We discuss the fabrication and microstructuring techniques of pillar s tructures made of high vacuum sputtered Fe/Cr multilayers and of molec ular beam epitaxy evaporated Co/Cu multilayers, for which we measured the giant magnetoresistance effect with the current perpendicular to t he multilayer plane from 4 K to 300 K. Using optical lithography and r eactive ion etching techniques we obtained structures with a typical h eight of 0.5 mum and a width ranging between 3 and 10 mum. For both Fe /Cr and Co/Cu multilayers we find an enhanced magnetoresistance with r espect to the in-plane case. The perpendicular magnetoresistance of th e Fe/Cr pillars strongly decreases with temperature, while for the Co/ Cu samples the temperature dependence is weaker, indicating electron-m agnon scattering processes of different strength.