Thermal and microstructural stability of the soft magnetic Fe60Co18Nb6B15Cu1 alloy

Temperature evolution of the coercivity of nanocrystalline samples of Fe60Co18Nb6B15Cu1 alloy with different crystalline fractions was measured from room temperature up to 690 K. Although room temperature coercivity increases as the nanocrystallization progresses, the thermal stability of the magnetic properties of the system is clearly enhanced as the crystalline volume fraction increases. Microstructure was characterized using room temperature Mِssbauer spectra which can be interpreted on the basis of the presence of three different regions: amorphous, crystalline and interface.