Nature of the first-order magnetic phase transition in giant-magnetocaloric materials

This thesis reports on advanced characterizations of giant magnetocaloric materials that show a first order magnetic phase transition (FOMT). The results are of great interest not only for the design of new magnetic refrigerants, but also for a better understanding of the FOMT. This thesis paves the way for further developments and understanding...

Thermomagnetic studies on transition metal pnictides

The magnetocaloric effect (MCE) consists, in simple terms, in the heating of a magnetic material by the application of an external magnetic field. This can be easily understood if one but imagines a magnetic material with randomly applied spins; as a magnetic field is applied the spins will tend to alight with this field and as a result the...

Magnetic structure and phase formation of magnetocaloric Mn-Fe-P-X compounds

This thesis presents a study of the crystal and magnetic structure, the magnetocaloric effect and related physical properties in Mn-Fe-P-X compounds. The influences of boron addition in (Mn,Fe)2(P,As) compounds have been studied. It is found that boron atoms occupy interstitial sites within the basal plane. First order magnetoelastic phase...

Moment formation and giant magnetocaloric effects in hexagonal Mn-Fe-P-Si compounds

Limited resources and the wish for improved prosperity call for efficient use of energy. The UN Advisory Group on Energy and Climate Change recommends a target of 40 % improved efficiency by 2030. Materials research can contribute significantly to reach this target. Magnetic refrigeration offers potential to achieve a 50 % higher energy...

First-order phase transitions and giant magnetocaloric effect

Modern society relies on cooling technology for food safety, comfort and medical applications. The solid-state cooling technology known as magnetic refrigeration is one of the most promising techniques to replace the current vapor-compression cooling technology. To date, the search for suitable materials with a large magnetocaloric effect (MCE)...