Amorphous magnetic alloys

Magnetically soft materials are important in electrical engineering. Amorphous magnetic alloys (AMA) are characterized by the absence of crystalline structure. Their existence was regarded as impossible in principle until 1960, but they have become traditional magnetic materials in many industrial nations; they are widely used as magnetic systems in transformers, electric machines, and elsewhere. The development of a high-speed method of obtaining thin strip (thickness 5-50 μm) - by continuous casting of liquid metal in the form of a plane jet and cooling at a rate of around 10 6 K/sec on the surface of a rotating disk - has permitted the large scale production of magnetically soft material that is comparable in cost with electrical-engineering steel(EES) but has better properties. This material, like EES, is based on Fe but contains, in addition to C and Si, B and P in a total quantity of around 20 at.%. The properties of AMA will be considered within the framework of the larger family of rapidly quenched magnetically soft materials.