Spin fluctuations in the (Nd,Lu)Mn/sub 2/ system

Using Gruneisen relations for the thermal expansion and the specific heat of (Nd,Lu)Mn/sub 2/ compounds, we succeeded in defining separate contributions, ascribed to electron excitations, lattice contributions and crystal-field effects in the Nd sublattice, with Gruneisen parameters /spl Gammasub e/=3.5, /spl Gammasub ph/=0.7 and /spl Gammasub Nd/=-3.0, respectively. After subtracting these contributions from the measured specific heat and thermal expansion, we applied the same analysis to the remaining part, ascribed to the Mn sublattice. In this way, we identified a spin-fluctuation contribution and a contribution ascribed to the antiferromagnetic ordering of 'local' Mn moments. The latter contribution disappears at substitution of 30% of Nd by Lu. The spin-fluctuation contribution is found in the complete concentration range of the Nd/sub 1-x/Lu/sub x/Mn/sub 2/ compounds.<>