Realization of multifunctional shape-memory ferromagnets in all-d-metal Heusler phases

TL;DR

This paper demonstrates the creation of all-d-metal Heusler ferromagnetic shape-memory alloys, showcasing their tunable transformation temperatures and strong ferromagnetism through strategic d-metal doping.

Contribution

It introduces a novel all-d-metal Heusler phase with multifunctional properties, expanding the material design space beyond traditional p-element containing alloys.

Findings

Successful synthesis of all-d-metal Heusler phases.

Doping with Ti and Co tunes transformation temperatures and magnetic properties.

Observation of magnetic-field-induced martensitic transformations.

Abstract

Heusler ferromagnetic shape-memory alloys (FSMAs) normally consist of transition-group d-metals and main-group p-elements. Here, we report the realization of FSMAs in Heusler phases that completely consist of d metals. By introducing the d-metal Ti into NiMn alloys, cubic B2-type Heusler phase is obtained and the martensitic transformation temperature is decreased efficiently. Strong ferromagnetism is established by further doping Co atoms into the B2-type antiferromagnetic Ni-Mn-Ti austenite. Based on the magnetic-field-induced martensitic transformations, collective multifunctional properties are observed in Ni(Co)-Mn-Ti alloys. The d metals not only facilitate the formation of B2-type Heusler phases, but also establish strong ferromagnetic coupling and offer the possibility to tune the martensitic transformation.