THE ANTIFERROMAGNETIC-FERROMAGNETIC TRANSITION OF CE2PD2.04SN0.96 STANNIDE

Magnetic measurements and a neutron diffraction study have been perfor med on a polycrystalline sample of Ce2Pd2.04Sn0.96. Two magnetic trans itions are observed at TN=4.8(2) K (antiferromagnetic transition) and T-C=3.0(2)K (ferromagnetic transition) respectively. The antiferromagn etic Ce2Pd2.04Sn0.96 structure is an incommensurate one, described by Ce3+ magnetic moments sinusoidally modulated along the tetragonal axis (P4/mbm crystalline space group): the propagation vector q=(qx, 0, 0) is thermally dependent, varying from qx=0.112(3) at T=4.5 K to 0.075( 3) at T=2.8 K. The ferromagnetic structure is described by magnetic mo ments parallel to c-axis (M=1.86(3) mu(B)/Ce3+ at T=1.5 K). In the 2.8 K less than or equal to T<3.4 K temperature range, both ferro- and an tiferromagnetic phases coexist in the stannide. Copyright (C) 1996 Els evier Science Ltd.