Melt-Spun Ribbons of Shape-Memory Ferromagnets: Structure, Magnetic and Thermomechanical Behavior and Prospects for Application in the Sensor and Actuator Technology

摘要

Ribbons made of the Heusler alloy Ni_(53)Mn_(24)Ga_(23) are used for studying the physical properties and the application potential of a new functional material, namely, melt-spun ribbons of a shape-memory ferromag-net. The structure of grains and martensitic and magnetic domains, as well as the magnetic properties of melt-spun ribbons of this alloy, are studied experimentally as functions of the degree of annealing of the microcrys-talline structure. For a ribbon-bending deformation, the deformation-temperature-load dependences are obtained using a specially developed multipoint procedure. The shape-memory effect characterized by multiple reversible bending deformations exceeding 1.4% is demonstrated. Promising designs of devices using the temperature and pressure sensitivity of the shape and magnetic susceptibility of ribbons are discussed concerning the application of these devices in sensor and actuator technology.