Eur. Phys. J. B 14, 83-90 (2000)
https://doi.org/10.1007/s100510050109

On the 240 K anomaly in the magnetic properties of LiNiO₂

¹ Laboratoire MATériaux: Organisation et Propriétés, CNRS, Case 151, Faculté des Sciences de Saint-Jérôme, Université d'Aix-Marseille III, 13397 Marseille Cedex 20, France
² Institut de Chimie de la Matière Condensée de Bordeaux, CNRS, École Nationale Supérieure de Chimie et Physique de Bordeaux, 87 avenue du Docteur Albert Schweitzer, 33608 Pessac Cedex, France

Received: 14 May 1999
Revised: 5 August 1999
Published online: 15 March 2000

Abstract

In this work, results of X-band ESR spectroscopy, ac-magnetic susceptibility and X-ray powder diffraction measurements on LiNiO₂ (x = 0.02 and x = 0.07) are presented and discussed. While the susceptibility of the compound with x = 0.02 is shown to follow a Curie-Weiss law, with a Weiss temperature of the order of 30 K, the compound with x = 0.07 is found to order ferromagnetically below K. However, an additional anomaly is observed in the magnetic properties of this latter compound at around 240 K. We attribute this anomaly to the presence of macroscopic Ni-rich regions which order ferrimagnetically below this temperature. This phenomenon is different from the bulk ferromagnetism that occurs at much lower temperatures, and allows us to discard earlier suggestions proposed in the literature in which the 240 K anomaly has been considered as denoting an intrinsic phenomenon.