Specific-heat studies of RCu4Al8 compounds (R=Er,Y)

Specific-heat measurements have been performed on the tetragonal ThMn12-type compound ErCu4Al8 and YCu4Al8 in the temperature range 1.5-200 K. A sharp peak in the specific heat, signals the antiferromagnetic transitions at T-N=5.18 K. In order to separate out the effect of the Er sublattice we have also performed measurements on the YCu4Al8, compound in the same temperature range. From the temperature dependence of the magnetic contribution to the specific heat of ErCu4Al8 we obtained the temperature dependence on the magnetic entropy and discuss our results in terms of the crystal field level scheme proposed earlier from inelastic neutron scattering. (C) 1998 American Institute of Physics. [S0021-8979(98)53411-1].