Tuning Magnetoelastic Transitions in Mn2Sb-based and Fe2Hf-based Magnetocaloric Materials

Magnetic refrigeration is based on the magnetocaloric effect (MCE) and has attracted considerable attention due to its potentially higher energy efficiency, environmental friendliness and quietness compared to conventional vapour compression refrigeration. Boosting giant MCE materials with a magnetoelastic transition into commercial applications requires not only insights into the coupling between its magnetism and the lattice, but also the correlation between macroscopic performance and microstructure. In this thesis, the fundamental physical properties, including crystal structure, microstructure, magnetic structure, negative thermal expansion behaviour and the magnetocaloric effect, are studied in Mn2Sb-based intermetallic compounds with an antiferromagnetic-to-ferrimagnetic transition and Fe2Hf-based Laves phase compounds with a ferromagnetic-to-antiferromagnetic transition...