Magnetic properties of hexakis(pyridine N-oxide)nickel(II) tetrafluoroborate

Abstract

The magnetic anisotropy of the title compound has been determined from 4.58 to 300 K and the average suscepti-bility has been measured down to 1.98 K at field strengths ranging from 10 to 50 kG. The results are interpreted on a point-charge model for D_3d symmetry using the parameters A₂⁰〈r²〉=925 cm^–1. ρ₄= 4 920 cm^–1, F₂= 1 306 cm^–1, F₄= 93 cm^–1, ζ= 550 cm^–1, and k= 1.0. It is suggested that the trigonal distortion of the nickel ion increases as the temperature is decreased to 100 K. The low-temperature anisotropy and magnetization are consistent with the compound being antiferromagnetic with T_N < 2 K.