Microfabricated synthetic ferrimagnetic elements and their application to high density memory devices

点击翻译按钮获取中文摘要

Synthetic ferrimagnetic films and exchange biased bilayers were microfabricated by focused ion beam, and their magnetic domain structures were imaged by magnetic force microscopy. In addition, imaging technique using magnetic X-ray microscope was investigated.(1) NiFe/Ru/NiFe synthetic ferrimagnetic films were prepared by magnetron sputtering and their magnetic properties were measured. Sufficient antiferromagnetic coupling was confirmed to obtained by optimizing the sputtering condition.(2) Square, rectangular, and ellipsoid magnetic elements were fabricated by focused Ga^+ ion beam having 〜100 nm diameter. Closure domain structure was observed for the squared NiFe(12 nm)/Ru(0.3 nm)/NiFe(10 nm) elements, and single domain structure was obtained in the 1:3 rectangular and ellipsoid elements. The dependence of the domain structure on the film construction was also investigated.(3) Domain structure recorded by a magnetic field modulation method on the magneto-optical recording media was imaged by using transmission X-ray microscope. The small marks less than 100 nm lengths were found to be clearly imaged by using X-ray microscope. The dependence of the minimum mark length on the film composition was also investigated. The experimental results were found to be explained by the simulation based on Huth's model.