In my scientific work, I investigate hyperfine interactions using Mössbauer spectroscopy - the technique which exploits the phenomenon of non-reflective nuclear resonance. Due to its isotopic specificity, I deal mainly with iron compounds, in which the nuclei of the naturally-occurring 57Fe isotope serves as a local probe in the material. Thanks to the correlation of hyperfine interactions with structural and magnetic ordering, their study, together with information provided by other experimental methods or calculations from the first principles, contributes to a deep understanding of studied systems even at atomic level.
Current miniaturization efforts have focused the scientific interest on magnetic nanoparticle systems and other low-dimensional structures. As a result of the particle size reduction, the influence of surface layers increases, giving rise to completely new properties with potential applications in biomedicine, technology and ecology. Reasonable economic costs and low toxicity of functionalized nanomagnets and composites based on iron oxides have allowed their rapid expansion and further development in recent decades. We have achieved significant results in the research of various Fe2O3 polymorphs and the recently discovered ε-phase, and X-substituted ferrites (X,Fe)3O4 as a contrast agent for magnetic resonance imaging (MRI) or magnetic particle imaging (MPI).
Other materials of interest are modern alloys (amorphous and nanocrystalline metallic glasses, Heusler and 3d-4f intermetallic alloys), for which the study of hyperfine interactions sheds light on the relationship between different types of structural modifications and magnetic ordering. In this case, the modifications are made by substitutions on purpose, or by exposure of the material to harsh conditions such as intense radiation, high temperature, or the presence of corrosive agents that the material necessarily undergoes in industrial applications.