Spin-phonon coupling and magnetoelectric properties: EuMnO3 versus GdMnO3

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Ferreira, WS (Autor) Outra; Agostinho A Moreira (Autor) FCUP; Almeida, A (Autor) FCUP; Chaves, MR (Autor) Outra; Araujo, JP (Autor) FCUP; Oliveira, JB (Autor) FCUP; Machado M M Da Silva (Autor) FCUP; Sa, MA (Autor) Outra; Mendonca, TM (Autor) Outra; Simeao S Carvalho (Autor) FCUP; Kreisel, J (Autor) Outra; Ribeiro, JL (Autor) Outra; Vieira, LG (Autor) Outra; Tavares, PB (Autor) Outra; Mendonca, S (Autor) Outra

Revista

Título: Physical Review B - Condensed Matter and Materials Physics

Vol. 79

ISSN: 1098-0121

Editora: American Physical Society

Indexação

ISI Web of Knowledge - 110 Citações

Scopus - 111 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Física

Outras Informações

ID Authenticus: P-003-NMQ

DOI: 10.1103/physrevb.79.054303

Abstract (EN): Correlation between spin-phonon coupling and the magnetoelectric properties of EuMnO3 and GdMnO3 were investigated using ceramic samples in this work. The experimental results evidence a stronger spin-phonon coupling in GdMnO3 than in EuMnO3, as well as a clear anomaly in the phonon contribution for the dielectric constant. This anomaly is located at the paramagnetic-incommensurate antiferromagnetic phase-transition temperature of GdMnO3, corroborating the existence of a magnetoelectric effect in this system. The absence of the magnetoelectric effect in EuMnO3 is due to the existing disorder revealed in this compound by the striking thermal metastability and the large decrease in the activation energy associated with the dielectric relaxation processes. This kind of behavior has no counterpart in GdMnO3. In fact, it has been confirmed that the existence of spin-phonon coupling is not a sufficient condition for the existence of magnetoelectric property, and other mechanisms have to be considered in order to understand the magnetoelectric properties.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10