Magnetic susceptibility of LaxCe1-xF3 single crystals

The magnetic susceptibility of LaxCe1-xF3 single crystals, for 0 < x less t han or equal to 0.5, has been measured from 4 up to 300 K in a magnetic hel d B approximate to 0.2 T applied parallel to the crystallographic a-axis (p erpendicular to the c-axis). The effective Bohr magneton number p(eff) and paramagnetic Curie temperature theta(p) have been obtained, using the Curie -Weiss law in the temperature range 100-300 K. The interconfiguration excit ed energy E-ex, the spin-fluctuation temperature T-sf, and the g-values, co rresponding to three Kramers doublets in the F-2(5/2), ground multiplet of Ce3+ ion in LaxCe1-xF3 have been determined, using quantum theory of parama gnetic susceptibility. The mixed-valent and crystal held effects influence significantly the g-values. The effect of the dilution of the paramagnetic Ce3+ ions with diamagnetic La3+ ions is also discussed. (C) 2000 Elsevier S cience B.V. All rights reserved.