Les couches minces à base de terres rares ont-elles un avenir technologique ?

The future of rare earth thin films

Laboratoire des éléments de transition dans les solides, e.r. 060210, C.N.R.S., Meudon

Abstract

Materials as thin films have known several technological developments in the last twenty years. Numerous applications have been realized. This paper presents some of these recent applications in the rare earth field and also may be, some of the future new developments of laboratory works. The field of investigations will concern only materials which contain at least one rare earth element (lanthanide series, from La to Lu, Sc and Y).

The first chapter presents a rapid survey of the experimental procedures relative to the preparation and to the analytical characterization of thin films. The second chapter gives a summarized description of technological applications in various fields of research (dielectric, photovoltaic cells, electronic, supraconductivity. chemical radiology, bio-corrosion,...) The last chapter is devoted to magnetic thin films, peculiarly to their magneto optic and thermomagnetic properties, and also to the new materials which are used at the present time in industry and research laboratories. A comparison is drawn of the advantages and disavantages of amorphous thin films (rare earth-3d transition metals) versus garnets. The problem of magnetic bubbles being one of the more important property for memory computers.