This project examined how atomic structure governs magnetic behaviour in selected intermetallic alloys, with the aim of clarifying structure–property relationships relevant for both fundamental magnetism and energy-efficient technologies. Magnetic intermetallics provide a versatile platform where subtle structural changes can lead to profound differences in magnetic order, making them promising candidates for applications such as magnetic refrigeration and advanced magnetic devices.
Neutron diffraction was the central technique used to resolve magnetic structures with high precision. Single-crystal neutron diffraction enabled unambiguous determination of complex spin arrangements in Tsai-type quasicrystal approximants, revealing non-collinear and non-coplanar magnetic orders and the effects of structural modifications on magnetic disorder. Neutron powder diffraction was applied to magnetocaloric materials, including Fe₂P-based and RE₂In compounds, uncovering composition-driven transitions between ferromagnetic, commensurate, and incommensurate magnetic states. Complementary X-ray diffraction supported the structural analysis.
The results demonstrated the extreme sensitivity of magnetic ordering to composition and crystal structure, particularly in Fe₂P-based systems where small substitutions drastically altered magnetic behaviour. By establishing clear links between structure and magnetism, the work provided valuable design principles for tuning magnetic properties and advanced the development of materials for next-generation, energy-efficient cooling technologies.