Magnetic domain and domain-wall imaging of submicron Co dots by probing the magnetostrictive response using atomic force microscopy

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.An approach to image the domains and domain walls of small ferromagnetic entities using atomic force microscopy(AFM), with a nonmagnetic AFM probe, has been developed. Exciting the sample in an external acmagnetic field, the distribution of magnetostrictive response at the surface is detected. By this technique, the domains and domain walls of submicron Co dots have been imaged with a 1 nm lateral resolution. In elliptical Co dots with a 350-nm-long axis on a triangular lattice array with 400 nm periodicity, we find evidence for two domains with opposite magnetization orientation across a wall. The domain-wall width in these dots is found to be about 35 nm. Furthermore, we observe a ferromagnetic alignment of the domains in the neighboring dots, which suggests a magnetostatic interaction among the dots