resumo
The effect of Mn doping on crystal structure and magnetic behavior of the polar antiferromagnetic and antipolar weak ferromagnetic phases of the Bi1-xLaxFeO3 system was investigated. Both reference compounds, Bi0.87La0.13FeO3 (space group R3c, tilting scheme (a(-)a(-)a(-))] and Bi0.82La0.18FeO3 [space group Pnam, tilting scheme (a(-)a(-)c(+))/(a(-)a(-)c(-))], were shown to undergo the Mn doping induced structural phase transformation towards the average Imma (a(-)b(0)a(-)) symmetry. Magnetization measurements performed for the compounds with the close to maximal manganese concentration (y = 0.4) found complex temperature-dependent behavior that can be indicative of a spin-reorientation transition. Enhanced spontaneous magnetization characteristic of the Mn-enriched x = 0.13 and x = 0.18 samples at low temperature is consistent with a competitive character of the superexchange interactions peculiar to the Fe/Mn containing perovskite systems. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759435]
palavras-chave
BISMUTH FERRITE; WEAK FERROMAGNETISM; PHASE-TRANSITIONS
categoria
Physics
autores
Khomchenko, VA; Troyanchuk, IO; Karpinsky, DV; Das, S; Amaral, VS; Tovar, M; Sikolenko, V; Paixao, JA
nossos autores
Projectos
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
agradecimentos
This work was supported by funds from FEDER (Programa Operacional Factores de Competitividade COM-PETE) and from FCT-Fundacao para a Ciencia e a Tecnologia under the Project PEst-C/FIS/UI0036/2011, PEst-C/CTM/LA0011/2011, PTDC/FIS/105416/2008, program