Rational approaches to the design of magnetocaloric materials

The magnetocaloric effect (MCE) is a thermal response of a magnetic material to a change in an external magnetic field. With the discovery of materials exhibiting a giant magnetocaloric effect in the vicinity of room temperature, several applications of this phenomenon have been proposed. First is the magnetic refrigeration, which can serve as a more eco-friendly alternative to conventional vapour-compression cooling systems. The second is the magnetic energy conversion using thermomagnetic motors and generators. It allows to transfer waste heat - currently an untapped resource – into electricity, therefore, increasing the energy efficiency of various types of industries. The development of devices for these applications facilitated the need for an optimal material to fit all the practical requirements. To this date, only a handful of materials are considered viable for commercial implementation, among which (Mn,Fe)2(P,Si) alloys, Ni-Mn-based Heusler alloys and La(Fe,Si)13 alloys are most prominent.

The goal of this thesis is to identify new promising magnetocaloric materials and improve known material systems using a combination of experimental techniques, ab initio modelling and database screening.