Kazushi Yamauchi

Properties of Fe‐Al‐Si‐N thin films prepared by N2 reactive sputtering

We have attempted to prepare Fe‐Al‐Si‐N films by rf magnetron sputtering in an atmosphere of Ar+N2, employing an Fe‐Al‐Si target, and investigated the influence of nitrogen on the properties of sendust alloys. Some properties, such as Vicker’s hardness and electrical resistivity of the films, were improved in the presence of nitrogen. In addition, the Fe‐Al‐Si‐N films interestingly show superior magnetic properties to those of sendust films. For example, effective permeability at 1 MHz of the film, prepared under the selected conditions, reached a maximum of approximately 4000, exceeding 2200 of our standard sendust film. The microstructure of Fe‐Al‐Si‐N and Fe‐Al‐Si films has been observed using scanning electron microscopy. As a result, we have found a difference in microstructure between the nitrogen‐containing films and the regular films.

Magnetic properties of Cr/Ni multilayered films

Abstract Cr/Ni thin films with a layered structure are formed by the magnetron sputtering method. The films are thermally stable at temperature up to 670 K. The crystallographic structures of films with small periodicities are bcc with the (110) plane parallel to the film for films with Cr layers thicker than Ni layers and fcc with the (111) plane parallel to the film for films with Cr layer the same or thinner than Ni layers. The paramagnetism is observed in the films with Ni layer thickness less than 8 A. The ferromagnetic Curie temperature is only determined as a function of Ni layer thickness regardless of the Cr layer thickness. Concerning the magnetic moments of the films it is supposed that below 4 A Ni layer in contact with Cr layer are nonmagnetic and the other Ni layer region holds the same magnetization of bulk Ni.