High-resolution magnetic imaging of domains in TbFe by force microscopy

Abstract

High-resolution images of domains written in a magnetic thin film have been obtained for the first time using force microscopy. The sample consisted of 500-Å-thick Tb19Fe81 with magnetization of 109 emu/cm3. Micron-sized magnetic domains were thermomagnetically written in the sample using a focused laser beam. Domain images were obtained by observing the magnetic interaction of the sample with a small vibrating magnetized iron tip. Typical observed force gradients were in the range 0.8×10-4-6×10-4 N/m and the forces were in the range 10-12-10-11 N. The spatial resolution of the technique was on the order of 1000 Å. This was sufficient resolution to see irregularities in those laser written marks which were recorded using low bias field.