Recent efforts for miniaturization of functional devices concentrate the scientific interest on systems of magnetic nanoparticles and other low-dimensional structures. Novel properties arise with the decrease of the particle sizes due to the growing influence of the surface effects. Motivated by their broad application potential connected with– especially in biomedical (contrast-increase agents for magnetic resonance imaging, local magnetic hyperthermia, magnetically-driven transport of therapeutic complexes, magnetic particle imaging, magnetic manipulation of labelled cells, studies of cell internalisation processes and performance in vivo) and biophysical (synergic water splitting, environmental catalysis) research - the magnetic cores are optimized to meet the requirements of target application. The nanoparticles with nearly monodisperse size and shape distributions are adjusted by suitable substitutions to alter their intrinsic magnetic properties (magnetization and magnetocrystalline anisotropy) and covered by biologically inert of functional surface coatings.
In the Laboratory of Mössbauer spectroscopy, we focus on the hyperfine interactions in iron oxide nanomagnets ((X,Fe)2O3 and its novel ε-phase, (X,Fe)3O4, iron oxohydroxide) and their nanocomposites in various matrices (amorphous SiO2, Cu metal). For this purpose we use the combination of Mössbauer spectroscopy and NMR with high resolution yielding a slightly different and complementary spectrum of information. With respect to the isotope specificity of both methods, we deal with the iron compounds where in particular the nuclei of the stable isotope 57Fe is the local probe. The detailed studies devoted primarily to structure and magnetism correlations allow for detailed understanding and progressive development of materials with improved properties.