INVESTIGATIONS OF MAGNETIC PHASES OF INTERMETALLIC ERBIUM-COMPOUNDS

The Mössbauer effect of the 80.6 keV γ-transition of Er166 has been employed to study the temperature dependence of the nuclear hyperfine splitting of Er166. The Er isotope was introduced into the intermetallic compounds ErCo2, ErCo0.5Ni0.5, ErCoNi, ErNi2 and ErAg. Except for ErCo2, all the compounds exhibit a behaviour typical for electronic relaxation phenomena. The system ErCo2 shows at 35 °K a magnetic phase transition of the first order which is discussed in the framework of the theory of Bean and Rodbell. Calorimetric data, low-temperature X-ray measurements and magnetization data are in agreement with the Mössbauer data. In ErAg and in ErNi2 the Er3+-moment is partially quenched by the interaction with the crystalline electric field. The ErCo2 data may be interpreted in terms of an undisturbed {Mathematical expression} multiplet. © 1969 Springer-Verlag.