The crystal structure of the heusler alloys

Abstract

Beginning in the year 1898 Heusler discovered as a series of ferromagnetic alloys, the most important containing copper, manganese, and aluminium. They are characterized by remarkable magnetic properties, because although composed only of paramagnetic or diamagnetic elements, they become ferro-magnetic after suitable heat treatment. Various explanations of this property have been advanced, but it was usually considered to be due to the formation of a series of solid solutions of the type (CuMn) 3 Al, in which the proportions of copper and manganese may be varied within fairly wide limits. The Heusler alloys have been repeatedly investigated by means of X-rays. Young, using molybdenum radiation examined alloys of two different compositions. He found that one was face-centred cubic, while the other was a mixture of face-centred and body-centred cubic structures. The mixed alloy was the more magnetic.