Effect of Eu substitution on the crystallographic and magnetic properties of the BiMn2O5 oxide obtained by urea combustion

Nenhuma Miniatura disponível

Data

2014-09-01

Orientador

Coorientador

Pós-graduação

Curso de graduação

Título da Revista

ISSN da Revista

Título de Volume

Editor

Elsevier B.V.

Tipo

Artigo

Direito de acesso

Acesso restrito

Resumo

Polycrystalline oxide materials with nominal compositions BiMn2O5 and Bi0.9Eu0.1Mn2O5 were obtained by urea combustion. Crystallographic studies using X-ray diffraction and Rietveld Refinement techniques showed the formation of single-phase samples for both compositions, crystallizing in a mullite-type orthorhombic perovskite structure, space group Pbam (Z=4). Replacement of Bi+3 by Eu+3 promoted a slight distortion and a unit cell contraction due to a decrease of the c-parameter for Bi0.9Eu0.1Mn2O5. The SEM/EDX techniques confirmed the formation of single-phase materials with excellent mapping distribution. Magnetic measurements showed different behaviors: BiMn2O5 is an antiferromagnet (AFM) with a Neel temperature (T-N) of 41 K and a Curie-Weiss temperature Theta(CW) of -277 K, while Bi0.9Eu0.1Mn2O5 displayed a ferrimagnetic behavior with a T-C of 44K and Theta(CW) of 270 K. The role of Eu+3 and the mechanisms responsible for the magnetic transition are discussed on the basis of chemical bonds and exchange interactions. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Descrição

Idioma

Inglês

Como citar

Ceramics International. Oxford: Elsevier Sci Ltd, v. 40, n. 8, p. 13643-13648, 2014.

Itens relacionados