Magnetoelastic Coupling in Mn-Fe-P-Si Compounds

Mn-Fe-P-Si compounds are, to date, the most promising materials for refrigeration and energy conversion applications due to the combination of giant magnetocaloric effect (GMCE) and low material cost. The nature of magneto-elastic transition was studied on both length- and time-scales using neutron diffraction, muSR and Mӧssbauer spectroscopy techniques for Mn-Fe-P-Si compounds. The revealed strong spin-lattice coupling is responsible for the different magnetic orders, the tunability of the phase transition, and the excellent magnetocaloric properties in these compounds. This thesis contributes to a better understanding of the spin-lattice coupling and phase-transition behavior for Mn-Fe-P-Si compounds.RST/Fundamental Aspects of Materials and Energ