With high-pressure torsion, a method of severe plastic deformation, powder mixtures are processed to supersaturated solid solutions of high homogeneity with grain sizes in the ultrafine or nanocrystalline regime. To study the effect of magnetic dilution, binary systems consisting of ferromagnetic (Fe, Co) and diamagnetic elements (Cu, Ag) are investigated. The ratios and distributions of diamagnetic and ferromagnetic phases have a huge influence on the magnetic properties such as the hysteresis curves or Curie temperatures. Continuous magnetic dilution applies for systems with large miscibility gaps in their thermodynamical equilibrium. Due to the usage of consolidated powders as starting materials, the complete compositional range can be observed. In this study, the microstructure of binary supersaturated solid solutions is investigated using electron microscopy and diffraction techniques. Heat treatments can further improve the magnetic properties by precipitation of small ferromagnetic phases; thus, the microstructural changes during different heat treatments are observed.
This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 757333).