Formation of the Relaxed Amorphous Phase in Iron-Based Amorphous Alloys Monitored by Magnetic Relaxation Techniques

In this article, formation of the relaxed amorphous phase in the Fe
₇₄
Cu
₁
Cr
₂
Zr
₁
Si
₁₃
B
₉
amorphous alloy is examined by applying magnetic relaxation techniques. Numerical analysis of the relaxation curves (reluctivity versus time measured for samples annealed for 1 h at temperatures 300 K
$\le T_{\mathrm{ a}} \le700$
K) has shown that the coupling model (the so-called stretch exponential function) describes all the observed facts. In particular with increasing
$T_{\mathrm{ a}}$
, the relaxation intensity decreases about 17 times, the relaxation time decreases about three times and the coupling parameter decreases from 0.8 to 0.4. The latter corresponds to a gradual disappearance of correlation effects in free volume diffusion. All these characteristics are connected with the process of formation of the relaxed amorphous phase, free of iron nanograins, which consists of atomic iron clusters mainly of ferromagnetic order.