Research on factors influencing on the microwave permeability of nanocrystalline FeB alloys

Nanocrystalline FeB alloys have been prepared with optimized grain size and internal stress. Samples prepared under different annealing conditions are analysed by x-ray diffraction, and the permeability \mu(\omega) is measured by HP8510B Vector Network Analyser in the frequency range 2--18GHz. The results show that annealing leads to the growth of the grain size and reduces the internal stress, and smaller grain size and larger internal stress favours the magnetic dissipation.