Mössbauer and magnetization measurements in FeCr solid solutions

Mossbauer effect and magnetization measurements have been obtained for Fe‐Cr alloys having Cr concentrations c=0.20, 0.25, and 0.30. The magnetically split Mossbauer spectra have been analyzed by the procedure of Window1 to give the probability distribution of hyperfine fields P(H) as a function of temperature and concentration. This distribution is closely approximated by two Gaussians: one centered near H=0 and the other at a value of H1 which is concentration and temperature dependent. The halfwidths ΔH of these Gaussians are independent of temperature and concentration. Both H1 and the zero field magnetization are proportional to (T−Tc)1/2 with Tc=160±3 K and 255±3 K for c=0.25 and 0.30, respectively. For c=0.20, H1 goes to zero at Tc=60±3 K. The magnetization for this sample is strongly field‐dependent and the spontaneous magnetization difficult to obtain. These results are in general agreement with a suggestion of Shull and Beck2 that the Fe‐Cr solid solutions are mictomagnets for 0.09?c≡0.23 and ar...