Magnetic Phase Transitions and Electric Polarization in RMn2O5 Oxides


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

Possible phase transitions from paramagnetic to the magnetic phases in the RMn2O5 (R = Bi, Pr, La) compounds have been studied in the framework of a phenomenological approach based on a symmetry analysis. The basis functions of the irreducible representations of the space group for these compounds are determined, which are expressed in terms of the magnetic vector components. It was found from renormalization group analysis of two magnetic transitions that polarization appears in BiMn2O5 oxide when at least one of these transitions becomes a first-order transition as a result of spin fluctuations. It was shown that the commensurate antiferromagnetic phase resulting from magnetic phase transition of the second order in PrMn2O5 has no electric polarization because this polarization is forbidden by the symmetry of the system. The conditions under which the parameters of the thermodynamic potential must satisfy the realization of a second-order transition in LaMn2O5 to have been found. The line of the first-order phase transitions in this system and the critical point of the second-order phase transition line have been determined. It was shown that a dynamic electric polarization can form in the antiferromagnetic phase for this compound.

About the authors

V. V. Men’shenin

Mikheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences

Author for correspondence.
Email: menshenin@imp.uran.ru
Russian Federation, Ekaterinburg, 620108

Supplementary files

Supplementary Files
Action
1. JATS XML

Copyright (c) 2018 Pleiades Publishing, Ltd.