MAGNETIC-PROPERTIES OF CE3-XCEXSE - KONDO AND CRYSTAL-FIELD EFFECT( IN PB1)

Electron paramagnetic resonance (EPR) experiments were performed on a Pb1-xCexSe crystal at liquid-helium temperatures and show very clearly that the doublet Gamma(7) is the ground state for cerium ions. The cu bic symmetry is shown and the effective Lande factor for the Ce3+ is d etermined to be 1.354+/-0.003. An orbital reduction factor is introduc ed to explain the g experimental value. High-field magnetization resul ts are in good agreement with the EPR results. The nominal Ce composit ion in PbSe deduced from saturation of the magnetization, x = 0.0405 /- 0.0003, is very closed to the Value determined by microprobe analys is (x = 0.04). At 1.5 K, an antiferromagnetic interaction between the nearest-neighbor cerium atoms is found, J(ex)/k(B) = -0.715 K. The low -field magnetic-susceptibility results show that the magnetic moment o f cerium impurities is strongly temperature dependent, explained by th e presence of the crystal-held effect and the Kondo effect.