Material Dependence of Thermally Assisted Magnetization Reversal Properties in Microstructured Co/Pd Multilayers

Using extraordinary Hall resistance ( R H ) measurements, the material dependence of thermally assisted magnetization reversal (TAMR) was investigated for microstructured multilayers of [Co (0.17 nm)/Pd (0.80 nm)] N with N = 7 and 20, which exhibit markedly different magnetic properties. The threshold values of the external field ( H wth ) necessary for controlling the magnetization direction in TAMR, obtained by direct application of a current pulse to the sample, were 220 Oe for the N = 7 and 710 Oe for N = 20 samples. The values of H wth are found to be related to the magnetization saturation field at a critical temperature at which apparent coercivity decays.