Influence of thermal treatment on local structure and magnetic properties of Ni-Mn-Ga alloys

The influence of the thermal treatment on local structure and magnetic properties of Ni-Mn-Ga alloys has been studied using a nuclear spin echo technique and magnetometry. Nuclear magnetic resonance investigations showed that annealing leads to the formation of stoichiometric Ni/sub 2/-Mn-Ga. Excessive Mn (Ga) causes faults in the atomic layers interchange. According to X-ray data, this transformation is not accompanied by changes of lattice parameter. However this results in increasing Curie and martensite-austenite transformation temperature. The character of the transition can also vary.