Magnetization processes in rare earth intermetallic compound DyCu

We have investigated the temperature dependence of magnetic susceptibility χ and elastic constant cB, c′, and c44 of DyCu (P  m¯3m) at the temperatures between 2 K and 300 K in order to evaluate the exchange and quadrupole interaction coefficients by using a mean-field approximation. The following results are obtained; (i) χ shows the Curie–Weiss behavior in the paramagnetic phase, meaning that the 4f electrons are well localized. (ii) c44 in the paramagnetic phase shows small softening at temperatures near TN while cB and c′ do not. This result indicates that the dominant components of quadrupole moment are Oyz, Ozx and Oxy in the Γ5 symmetry. (iii) The estimated exchange and quadrupole interaction coefficients are determined to be (J1+2J2)S2/kB=−79 K and (G1+2G2)Q2/kB=−45 K, respectively. (iv) We propose the magnetic structure models of field-induced phases, and calculate the critical fields of magnetization processes in the [0 0 1], [1 1 0] and [1 1 1] directions by using above values of interaction coefficients. The calculated values are in agreement with the experimental ones.