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

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 La1 –xNdxCoO3 has been investigated to see how the behaviour characteristic of Nd[CoO3] changes to that of La[CoO3].