Crystallization in Fe76X2B22 (X = Cr, Zr, Nb) amorphous alloys

In the present paper crystallization in the Fe76X2B22 (X = Cr, Zr, Nb) amorphous alloys was examined by applying different experimental techniques (resistivity measurements, differential scanning calorimetry and X-ray diffraction). It was shown that alloying additions cause a slowing down of the diffusion processes which manifests in a shift of the nanocrystallization process into higher temperatures. This effect is discussed in the context of soft magnetic properties of examined materials. Activation enthalpy of crystallization determined from the DSC data strongly depends on alloying additions and is: 2.1, 2.1, 2.7 and 4.0 eV for Fe78B22, Fe76Cr2B22, Fe76Zr2B22, Fe76Nb2B22 alloys, respectively. The crystallization phenomenon in examined alloys proceeds via formation of αFe nanograins (nanocrystallization for Fe76Zr2B22 and Fe76Nb2B22) and the growth of αFe nanograins plus formation of boride Fe3B.