Magnetic properties of Co/Pt multilayers deposited on patterned Si substrates

Arrays of Si dots 400 nm squares with a spacing of 100 nm and a height of 2 00 nm were patterned on silicon substrates by electron beam lithography and reactive ion etching, and a Co/Pt multilayer was sputter-deposited on thes e patterned silicon substrates. The magnetic film covers the top of the dot s, the bottom of the grooves and to a much less extent the side-walls of th e dots. The magnetic properties were studied by magnetic force microscopy ( MFM). The Co/Pt multilayer exhibits perpendicular magnetic anisotropy and s ingle-domain magnetic dots are obtained. Our results indicate that the widt h of the switching field distribution of the dots is not due to magnetostat ic interactions but can be ascribed to a distribution of defects in the dot s. A statistical analysis of MFM images shows that no significant direct co upling is mediated by the magnetic deposit on the side-walls of the dots. ( C) 2001 Published by Elsevier Science B.V.