Advancing the functionality of magnetic shape memory alloys by doping and microstructure control

Anotace
The most prominent effect observed in magnetic shape memory (MSM) alloys is so-called magnetically-induced reorientation (MIR), i.e. a rapid (<1ms) giant straining (up to 12%) in a moderate (<1 T) magnetic field. The prototype MSM material is Ni-Mn-Ga alloys, which may soon find its place in emerging MSM applications. In this project we aim to enance the properties of these alloys by doping, with particular focus i) extending usable temperature range, ii) understanding the physical origins of the effects of doping on twin boundary mobility and twin microstructure, iii) demonstrating the doping-induced novel functionality and explaining the underlying physical principles. The concrete outputs will be: developed MSM alloys with extended temperature range, new MSM alloys with novel functionality, and related scientific understanding and publications. The results will impact physics of martenite, materials science, development of MSMAs, and application research and use of the MSMAs, and will be applied immediately in application research through the international collaborators.