EN
The room temperature Mössbauer spectra of ^{57}Fe were measured for the bcc Fe_{0.948}Cr_{0.052} solid solution quenched into water being at about 295 K from different temperatures not exceeding 1000 K, i.e. from the temperatures for which probabilities of formation of "clear" (Schottky) vacancies as well as vacancies forming the separate interstitial-vacancy (Frenkel) pairs are negligibly low. The obtained data were analysed in terms of concentration of unoccupied places in the 14-site surroundings of an ^{57}Fe Mössbauer probe in the sample. It turned out that the concentration of vacancies detected by the probe increases with temperature very rapidly - at the rate of about 10^{-4} K^{-1}. The result may suggest that the Mössbauer probe is sensitive to a possible thermal distortion of the lattice or creation of very close Frenkel pairs (the interstitial is the nearest neighbour of the vacant lattice site).