Institute of Physics of Materials AS CR, v. v. i. > Projects > Structure and magnetic properties of amorphous and nanocrystalline Fe(Ni)MoCuB based alloys

---

Structure and magnetic properties of amorphous and nanocrystalline Fe(Ni)MoCuB based alloys

Anotace

The main aim of the proposed project is to investigate experimentally the Fe(Ni)MoCuB system with small variations in composition and to explain the measured data using theoretical models. Iron-rich FeMoCuB compound belongs to NANOPERM-type of nanocrystalline materials that was, to date, not so frequently studied in comparison to compounds with Zr or Nb in place of Mo. The measurements will be done first on amorphous alloys. The obtained results will serve as an input for subsequent studies of nanocrystalline state. Depending on composition, the FeMoCuB amorphous alloy exists in the paramagnetic or ferromagnetic state at room temperature. The first investigations show some distinct properties as, e.g., shift in Curie temperature due to some relaxation effects evoked by annealing of the as-prepared amorphous alloy at temperatures below crystallization, different rate of crystallization in comparison to FeZr(Nb)CuB compounds, anomaly in the low-temperature magnetization bellow 200 K, etc. These properties have not been satisfactorily explained yet which calls for more detailed investigations. A wide spectrum of experimental methods (magnetic measurements, conversion electrons and gamma-ray Mössbauer spectroscopy, electrical resistivity, XRD, TEM, etc.) in the temperature range of 10 K - 1000 K and in applied fields up to 5 T will be employed. The experiments will be completed by theoretical modelling and electronic structure calculations which should yield an exhaustive physical view on the properties of the Fe(Ni)MoCuB system.