Title :
Spin fluctuations in the (Nd,Lu)Mn2 system
Author :
Kim-Ngan, N.H. ; Brommer, P.E. ; Franse, J.J.M.
Author_Institution :
Van der Waals Lab., Amsterdam Univ., Netherlands
fDate :
3/1/1994 12:00:00 AM
Abstract :
Using Gruneisen relations for the thermal expansion and the specific heat of (Nd,Lu)Mn2 compounds, we succeeded in defining separate contributions, ascribed to electron excitations, lattice contributions and crystal-field effects in the Nd sublattice, with Gruneisen parameters Γe=3.5, Γph=0.7 and ΓNd=-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 Nd1-xLuxMn2 compounds
Keywords :
Gruneisen coefficient; antiferromagnetic properties of substances; crystal field interactions; lutetium alloys; manganese alloys; neodymium alloys; specific heat of solids; spin dynamics; thermal expansion; (Nd,Lu)Mn2; Gruneisen relations; NdLuMn2; antiferromagnetic ordering; crystal-field effects; electron excitations; specific heat; spin fluctuations; thermal expansion; Antiferromagnetic materials; Entropy; Fluctuations; Lattices; Magnetic moments; Neodymium; Phonons; Temperature dependence; Thermal expansion; Uncertainty;
Journal_Title :
Magnetics, IEEE Transactions on
