Spin-phonon coupling and magnetoelectric properties: EuMnO3 versus GdMnO3

• Type: Article in International Scientific Journal
• Date: 2009

Authors

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

Journal

Title: Physical Review B - Condensed Matter and Materials Physics

Vol. 79

ISSN: 1098-0121

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 118 Citations

Scopus - 120 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10