Influence of Carbon on Spin Reorientation Processes in Er_2-xR_xFe₁₄C (R = Gd, Pr) - Mössbauer and Magnetometric Studies

Abstract

The Er2−xRxFe14C (R=Gd, Pr) polycrystalline compounds have been synthesized and investigated with 57 Fe Mössbauer spectroscopy and magnetic measurements. The spin reorientation phenomena were studied extensively by narrow step temperature scanning in the neighborhood of the spin reorientation temperature. Obtained Mössbauer spectra were analyzed using a procedure of simultaneous fitting and the transmission integral approach. Consistent description of Mössbauer spectra were obtained, temperature and composition dependencies of hyperfine interaction parameters and subspectra contributions were derived from fits and the transition temperatures were determined for all the compounds studied. Initial magnetization versus temperature measurements (in zero and non-zero external field) for Er2−xGdxFe14C compounds allowed to establish the temperature regions of reorientation, change of magnetization value during the transition process. The results obtained with different methods were analyzed and the spin arrangement diagrams were constructed. Data obtained for Er2−xGdxFe14C were compared with those for Er2−xGdxFe14B series.