Magnetoresistance is a physical property with many technological applications. The variation of the electrical resistance of a material with an external magnetic field makes it possible to convert a magnetic signal into an electric signal. Obviously, the stronger the phenomenon, the easier the conversion.

Industry seized on it to manufacture magnetic probes and for information storage. Much research effort has been made during the last 30 years on magnetoresistive systems and progress has been remarkable.

However a deeper understanding of the underlying phenomena is needed to improve performance. this requires the magnetism of the material to be analysed at the atomic scale and neutrons are a convenient tool to do so.