  Binding of 57Fe atoms in a metallic chromium was investigated in a Cr-Fe
alloy, containing less than 0.1 at% Fe enriched to ~95 % in 57Fe isotope, using
57Fe-site Mossbauer spectroscopy. The binding force was derived from the Debye
temperature, T_D, that, in turn, was calculated from the temperature dependence
of the central shift of the Mossbauer spectra recorded in the range of 80 to
330 K. Following a temperature dependence of the line width that shows a
minimum at ~155 K, two temperature intervals were considered: a low temperature
one (LT) ranging from 80 to 155 K, and the T_D - value of 292 (12) K or 279
(34) K, and a high temperature one (HT) ranging from 155 to 330 K with the T_D
- value of 399 (15) or 399 (25) K, depending on the fitting procedure. The
corresponding values of the harmonic force (spring) constant are: 35.4 N/m and
66.1 N/m or 33.8 N/m and 66.1 N/m for the LT and HT, respectively. This means
that in the HT range the binding force of 57Fe atoms by the Cr matrix is by a
factor of ~1.9 - 2 stronger than that in the LT range. This anomaly is possibly
related with a different polarization of the spin-density waves in the LT and
HT "phases".
