MAGNETIC-PROPERTIES OF THE CARBIDES Y2REC2, TB2REC2, ER2REC2 AND LU2REC2

Magnetic susceptibility measurements with a SQUID magnetometer reveal that the rhenium atoms in Y2ReC2 and Lu2ReC2 do not carry magnetic mom ents. The moments of the lanthanoid atoms in Tb2ReC2 and Er2ReC2 order antiferromagnetically below T-N = 96(2) and 18(1) K, respectively. Bo th compounds show metamagnetic transitions, and above the Neel tempera tures strong field-dependent paramagnetism was observed suggesting str ong paramagnetic anisotropies. The antiferromagnetic structures of bot h compounds are different, however, with the same propagation vector k = 0. They were determined from neutron powder data recorded in zero f ield at 1.5 K. The magnetic structures can be described with the basis functions [0, A(y), 0] and [G(x), A(y), A(z)] for the terbium and erb ium moments, respectively, using Bertaut's representation analysis.