Magnetic Phase Transitions and Magnetic Structures in Mn-based Compounds

The growing demand for energy highlights the need for developing more efficient and environmentally friendly technologies. Magnetic cooling based on the magnetocaloric effect is a promising alternative for compressor-based refrigeration. Among various magnetocaloric materials, Mn-based alloys appear especially attractive due to their low cost, high abundance and the potentially large magnetic moment density. We aimed to obtain a large magnetocaloric effect at room temperature in various non-toxic and inexpensive magnetocaloric materials. Thus, this thesis contains the study on the magnetism, magnetocaloric effect and (micro)structure of three families of Mn-based magnetocaloric materials: (Mn,Fe)2(P,Si), Mn3Sn1-xAxC antiperovskite carbides, MnNiSi half Heusler alloys. A particular part of this dissertation focuses on the elucidation of magnetic structures in antiperovskite carbides.