Magnetic phase transitions in the Ce(Fe1 − x Si x )2 compounds

Abstract

The structure of the Ce(Fe1 − xSix)2 compounds (with x ≤ 0.075) has been studied and, magnetic susceptibility, heat capacity, and Mossbauer effect have been measured. The compounds with x ≥ 0.05 are antiferromagnetic at low temperatures; as the temperature increases, the compounds become, at first, ferromagnetic and next paramagnetic. The temperatures of magnetic phase transitions have been determined using data on the magnetic susceptibility, and the magnetic phase diagram of the system has been constructed. The heat capacity has been measured and the data were used to calculate the entropy change upon magnetic phase transitions; it is 7.9 and 6.0 J/kg K for CeFe2 and Ce(Fe0.93Si0.07)2, respectively. An analysis of Mossbauer spectra for the alloys in the paramagnetic state allowed us to find that silicon atoms statistically substitute for iron atoms in the crystal lattice intermetallic.