Influence of the Preparation Method and Doping on the Magnetic and Electrical Properties of AgNiO2

✍ Scribed by Y.J. Shin; J.P. Doumerc; P. Dordor; C. Delmas; M. Pouchard; P. Hagenmuller

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 378 KB
• Volume: 107
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1993.1352

✦ Synopsis

Electrical and magnetic properties of delafossite-type (\mathrm{AgNiO}{2}) prepared either from (\mathrm{LiNiO}{2}) or from (\mathrm{NaNiO}{2}) as the precursors have been compared. The difference of behavior is attributed to the well known deviation from stoichiometry of (\mathrm{LiNiO}{2}) and to the presence of some (\mathrm{Ni}) atoms in the (\mathrm{Li}) layers whereas such effects may be neglected in (\mathrm{NaNiO}{2}). Magnetic interactions are antiferromagnetic ( (J<) (0)) in (\mathrm{AgNiO}{2}), in contrast to (\mathrm{LiNiO}{2}(J>0)). This result is ascribed to the evolution of the covalency of the Ni-O bonds. Transport properties are interpreted in the framework of a semimetal model. A comparative approach of the correlation between structure, chemical bond, and electronic delocalization in delafossite-, (\alpha-\mathrm{NaFeO}{2^{-}}), and perovskite-type nickel(III) oxides is proposed. (1993 Academic Press, Inc.