Induced ferroelectric phases in TbMn2O5

Autor(en)

Pierre Toledano, Wilfried Schranz, Gerhard Krexner

Abstrakt

The magnetostructural transitions and magnetoelectric effects reported in TbMn2O5 are described theoretically and shown to correspond to two essentially different mechanisms for the induced ferroelectricity. The incommensurate and commensurate phases observed between 38 and 24 K exhibit a hybrid pseudoproper ferroelectric nature resulting from an effective bilinear coupling of the polarization with the antiferromagnetic order parameter. This explains the high sensitivity of the dielectric properties of the material under applied magnetic field. Below 24 K the incommensurate phase shows a standard improper ferroelectric character induced by the coupling of two distinct magnetic order parameters. The complex dielectric behavior observed in the material reflects the crossover from one to the other transition regime. The temperature dependences of the pertinent physical quantities are worked out, and previous theoretical models are discussed.

Organisation(en)

Physik Funktioneller Materialien

Externe Organisation(en)

Université de Picardie Jules Verne

Journal

Physical Review B

Band

79

Anzahl der Seiten

7

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.79.144103

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/7620d1cc-a78b-4bd3-8bbf-4cab79e380fc