Coupling between phonons and magnetic excitations in orthorhombic Eu1-xYxMnO3

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Agostinho A Moreira (Autor) FCUP; Almeida, A (Autor) FCUP; Ferreira, WS (Autor) Outra; Araujo, JE (Autor) FCUP; Pereira, AM (Autor) FCUP; Chaves, MR (Autor) Outra; Kreisel, J (Autor) Outra; Vilela, SMF (Autor) Outra; Tavares, PB (Autor) Outra

Revista

Título: Physical Review B - Condensed Matter and Materials Physics

Vol. 81

ISSN: 1098-0121

Editora: American Physical Society

Indexação

ISI Web of Knowledge - 36 Citações

Scopus - 36 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Física

Outras Informações

ID Authenticus: P-003-9JD

DOI: 10.1103/physrevb.81.054447

Abstract (EN): In this work we present a detailed study of the structural and lattice-dynamic properties of Y-doped EuMnO3 ceramics (Eu1-xYxMnO3 with 0 <= x <= 0.5). A thorough analysis toward the correlation between both structural and Raman modes parameters has been undertaken. Our results provide evidence for two main structural distortions of MnO6 octahedra, arising from a cooperative Jahn-Teller and rotational distortions in these compounds. The temperature dependence of the B-1g symmetric stretching mode of the MnO6 units has revealed either a positive or negative shift regarding the pure anharmonic temperature dependence of the phonon frequency, which strongly depends on the Y concentration. This frequency renormalization is explained in terms of a competition between ferromagnetic and antiferromagnetic interactions. Frequency shifts observed well above the Neel temperature are likely associated with the coupling between phonons and electromagnons, which provides further grounds for the existence of strong spin-phonon coupling in this compound. Both polar and magnetoelectric properties ascertained for x = 0.2 provide clear evidence of the central role played by spin-phonon coupling in yielding the physical behavior of the Y-doped EuMnO3 system.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 12