Effect of Low Temperature Annealing Upon Magnetic Properties of FeMoCuB Metallic Glass

The influence of low temperature annealing on microstructure and magnetic properties of the Fe
₇₆
Mo
₈
Cu
₁
B
₁₅
metallic glass was studied. Non-monotonous change of the Curie temperature (T
_C
) of the amorphous phase in the samples subjected to isothermal annealing is observed. It is connected with structural relaxation of the amorphous matrix, which consequently yields chemical and/or topological modifications of the short-range order. After annealing at temperature well below the onset of crystallization, T
_C
first rises then assumes its original value. Structural rearrangement of the resonant
⁵⁷
Fe nuclei is directly seen from the Mössbauer spectra. Thermomagnetic properties of the Fe
₇₆
Mo
₈
Cu
₁
B
₁₅
alloy were studied in a wide range of measuring temperatures for understanding magnetic behavior of NANOPERM type metallic glasses exposed to low-temperature heat treatment, whereas the investigated alloys are still amorphous.