Magnetic phase transition and spin-reorientation transition of Cu/Ni/Fe/Cu(001) studied by photoemission electron microscopy

Magnetic phase transition and spin-reorientation transition in a Cu/Ni/Fe/Cu(001) system are investigated at room temperature using photoemission electron microscopy. For fixed Fe film thickness, the Cu/Ni/Fe/Cu(100) film exhibits two transitions with increasing Ni thickness: one transition corresponds to a paramagnetic to ferromagnetic transition, and the other transition corresponds to a spin-reorientation transition. A phase diagram is constructed in the Ni-Fe thickness plane to describe these two transitions. For each transition, we find that the Ni transition thickness changes monotonically as the Fe film thickness increases from 0 to 4 ML, and then remains a constant value for Fe thickness in the range of 5-11 ML. These results are attributed to the ferromagnetic and antiferromagnetic phases of the fcc Fe film and to the in-plane Ni/Fe interfacial magnetic anisotropy.