Structural anomalies at the magnetic transition in centrosymmetric BiMnO$_3$

The structural properties of BiMn$O_3$ were determined from neutron powder diffraction data as a function of temperature and magnetic field. The structure at all temperatures was found to be centrosymmetric with space group $C2/c$, which is incompatible with ferroelectricity. At T$_C\simeq 100 K$, w...

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Detalhes bibliográficos
Main Authors: Montanari, E, Calestani, G, Righi, L, Gilioli, E, Bolzoni, F, Knight, K, Radaelli, P
Formato: Journal article
Idioma:English
Publicado em: 2007
Descrição
Resumo:The structural properties of BiMn$O_3$ were determined from neutron powder diffraction data as a function of temperature and magnetic field. The structure at all temperatures was found to be centrosymmetric with space group $C2/c$, which is incompatible with ferroelectricity. At T$_C\simeq 100 K$, we observed the onset of a large magnetoelastic strain, proportional to the square of the magnetization. We interpret this structural rearrangement, together with the previously observed magnetodielectric anomalies, as due to the need to optimize the partially frustrated magnetic interactions.