Nanomagnetics: Behavior of nanostructured magnetic materials (wires and dots)
Professor Teruya Shinjo, International Institute for Advanced Studies, Japan

Professor Teruya SHINJO received his D.Sc. from Kyoto University, Japan in 1966. He entered in the Institute for Chemical Research, Kyoto University and became a full professor in 1984. He served as the director of the Institute from 1995 to 1997. Since 2002, he has been Professor emeritus of Kyoto University and is belonging to International Institute for Advanced Studies as a senior researcher. Main subjects of his works are; Mössbauer spectroscopic studies on magnetic materials, magnetic properties in ultrathin films and multilayers, giant magnetoresistance, and behavior of nanostructured magnetic systems prepared by electron beam lithography technique.

Presentation (4432kb)

Since the discovery of GMR (Giant magnetoresistance) in 1988, interplay of magnetism and transport phenomena has gathered much attention and the cultivation of the new field, "spintronics" has been initiated. Major subjects of spintronics are the basic studies on conduction of magnetically polarized electrons (spin current) and exploitation of novel devices using spin current. Materials to be used as the elements in spintronics are often requested to have nanoscale size. As for the sample preparation method to produce magnetic systems with very small size, roughly speaking, there are two ways: micro(nano)- fabrication techniques and self-organized processes. The latter is advantageous to prepare extremely small particles but the shape is not able to control. On the other hand, microfabrication techniques can control the size and shape of the sample and therefore nanoscale dots and wires are able to be prepared.

In this talk, several recent developments in the study of magnetic systems with wire and dot shapes carried out in Kyoto University are introduced. Domain wall (DW) in a wire sample is detected by magnetic force microscopy(MFM) and DW motion driven by magnetic field and also by electric current is investigated. In dot samples, vortex magnetic structure is formed and a perpendicular magnetization spot exists at each vortex center. Switching of core magnetization caused by magnetic field is observed by MFM and the motion of vortex core driven by electric current is studied.