Particle size effect on Néel temperature in Er<inf>2</inf>O<inf>3</inf> nanopowder synthesized by thermolysis of 2, 4-pentadione complex

Abstract

New synthesis routine based on thermal decomposition of an erbium complex with acetylacetonato ligand (2, 4-pentadione) was used to prepare nanosized Er2O3 with a particle size of 5 nm and a narrow size distribution. For the sake of comparison, the ultrafine- Er2O3 powder was prepared by precipitation and subsequent sintering. The magnetic susceptibility of nanosized Er2O3 indicates the antiferromagnetic ↔ paramagnetic transition at 1.8 K or lower, while in ultrafine such as in a bulk counterpart the transition was observed at noticeably higher temperature of ∼3.4 K. The decrease in Néel temperature, observed in the case of nanosized Er2O3 sample, was attributed to both particle surface and core effects. © 2007 Elsevier Ltd. All rights reserved.