Single-crystal magnetic properties of lanthanide complexes. Part X. Hexakis(antipyrine)holmium(III) tri-iodide

Abstract

The principal and average magnetic moments of hexakis(antipyrine)holmium(III) tri-iodide [antipyrine (antip) is 2,3-dimethyl-1-phenyl-Δ³-pyrazolin-5-one] have been measured in the temperature range 80—300 K. The results are interpreted within a point-charge crystal-field model of D_3h symmetry by use of 5/8 and 5/7 free-ion states as basis, corrected for the effects of intermediate coupling. A range of values for ρ₄ and ρ₆, the fourth- and sixth-order radial parameters, is fixed for Ho(antip)₆I₃ by the temperature-dependence of mean moments. For points within this range, anisotropies fix values of A₂°〈r²〉, related to the coefficient of the second-order crystal-field harmonic. Intermediate compromise values are: ρ₄= 350, ρ₆= 150, A₂°〈r²〉= 220 cm^–1.