Neutron scattering of magnetocaloric and barocaloric materials

Abstract

<p indent="0mm">Caloric materials are systems that exhibit significant thermal effects at phase transitions induced by external fields like temperature, pressure, stress, magnetic fields, and so forth. They can be used for the solid-state refrigeration through a designated cooling cycle. The core physical issue of caloric materials is the evolutions of atomic structures and interactions as a function of these driving forces in multiple spatial and temporal scales. State-of-the-art characterization techniques based on large-scale facilities such as neutron scattering are highly desirable in this case due to the powerful experimental abilities and versatile sample environments. In this review, the fundamentals of neutron scattering are first briefly introduced. Then, three typical systems are present as benchmarks, i.e., pressure-dependent neutron diffraction on magneto-structurally coupled Tb₅Si₂Ge₂, magnetic-field-dependent inelastic neutron scattering on inverse magnetocaloric Mn₅Si₃, and pressure-dependent quasi-elastic neutron scattering on colossal barocaloric plastic crystal C₅H₁₂O₂. By doing so, it is expected that <italic>in</italic>-<italic>situ</italic> neutron scattering techniques are promoted to clarify some fundamental issues in caloric materials.