Hyperfine magnetic interactions in Tb(Fe$_{1-x}$Al$_x$)$_2$ alloys

The structural and magnetic characteristics of phase transformations in Tb(Fe$_{1-x}$Al$_x$)$_2$ alloys with concentrations $x$ = 0–0.9 have been measured in the temperature range from 90 to 450 K. The temperature dependences of the hyperfine magnetic fields for each of local configurations of the nearest environment of iron atoms upon substitution of aluminum atoms for iron atoms have been found using Mössbauer spectroscopy.