A magnetic susceptibility study of spin-state transitions in rare-earth trioxocobaltates(III)

Abstract

Rare-earth trioxocobaltates(III), Ln[CoO₃], with Ln=Pr, Nd, Tb, Dy, and Yb exhibit low-spin to high-spin transitions of cobalt characterised by a maximum in the Δχ⁻¹ against temperature plots where Δχ is the cobalt contribution to the magnetic susceptibility. The susceptibility behaviour is distinct from that of La[CoO₃] which shows a plateau in the χ⁻¹-T curve accompanied by a structural transition. The temperature at which the Δχ⁻¹-T curve shows a maximum increases with the decrease in the size of the rare-earth ion. The susceptibility behaviour of solid solutions of La_1−xNd_xCoO₃ has been investigated to see how the behaviour characteristic of Nd[CoO₃] changes to that of La[CoO₃].