Effect of Mechanical Stress on Structure of Magnetization of Three-Layer Nanosized Disks

The contribution of magnetoelastic effects to the effective magnetic anisotropy of a three-layer film nanodisk (nonmagnetic metal/ferromagnet/nonmagnetic metal) was studied. The mechanical stresses at the lateral surface of the disk that are caused by two factors, i.e., unequal thermal expansion of layers and excess surface energy at the layers interfaces, were estimated. The case in which the contribution of magnetoelastic effects to the anisotropy is comparable with those of shape and crystalline anisotropies was discussed. It was shown that the main reason for the change in the local anisotropy field in the vicinity of a nanodisk edge was the mechanical stresses induced by the excess surface energy. The possible application of film nanodisks of nickel with a bilateral golden coating as “nanolancets” for noninvasive cell surgery of tumors was discussed.