Magnetic properties and magnetic interactions in chromium-rich Cr-Fe alloys

The results of magnetization measurements on several disordered b.c.c. Cr-Fe alloys with 1, 1.5, 2.4, 5.3, 12 and 14.2 at % of Fe are reported. The measurements were done in pulsed magnetic fields up to 330 kOe and for the two last alloys also in static magnetic fields up to 44 kOe as in function of temperature. The data support the recently proposed model of magnetic interactions in these alloys by Friedel and Hedman. For the alloys with iron concentration equal to and greater than 2.4 at % we observe, at low temperature, the occurence of a ferromagnetic component in the magnetization curves saturating at an external field of about 140 kOe arising from ferromagnetic iron-rich cluster. At liquid helium temperature the localized iron moments within such iron clusters increase from 1.4μ_B to 1.8μ_b when the iron concentration changes from 2.4 at % to 14.2 at %. At higher iron concentrations we observe a spin glass like transition connected with a freezing of ferromagnetic clusters at very low temperature. Both phase boundaries connected with supermagnetic-paramagnetic and superamagnetis-spin glass like transitions are given.