Magnetocrystalline anisotropy of (100) face-centered cubic Co structures deposited on Cu/Si(100)

Abstract

Face-centered cubic (fcc) Co in the (100) orientation has been recently grown using the technique of metal-metal epitaxy on silicon (MMES), with a (100)Cu seed. This enables the determination of the magnetocrystalline anisotropy of fcc Co by measuring its angular dependence of the in-plane magnetization. Using (100)Cu/Co/Cu structures with varying Co thickness between 25 and 500 Å, while keeping the Cu layers at 1000 Å each, an easier magnetization at low field along the [110] edge than that along the [100] one is seen for all the structures studied. The same angular dependence is also observed for the (100)Cu-Co superlattices. Such a crystalline anisotropy is similar to the one observed for bulk Ni crystal and the (100)Cu/Ni/Cu structures. The fcc Co films thus share the same magnetocrystalline anisotropy as fcc Ni, which is different from Fe. The body-centered cubic bulk Fe crystal shows an easier low-field magnetization along the [100] edge than the [110] one; the same has been observed for both the (100) Cr/Fe/Cr and Pd/Fe/Pd structures grown by the MMES technique.