Theory of magnetic phases of hexagonal rare earth manganites

TL;DR

This paper analyzes the complex magnetic phases of hexagonal rare earth manganites using group theory and Landau theory, revealing intricate phase diagrams and their experimental relevance.

Contribution

It introduces a phenomenological model with four magnetic order parameters to explain the magnetic phase behavior of RMnO3 compounds.

Findings

Coupling of order parameters creates complex phase diagrams.

Model results align with experimental observations.

Multiple magnetic phases are explained by the developed theory.

Abstract

The magnetic phases of hexagonal perovskites RMnO_3 (R=Ho, Er, Tm, Yb, Sc, Y) are analysed using group theory and the Landau theory of phase transitions. The competition between various magnetic order parameters is discussed in the context of antiferromagnetic interactions. A phenomenological model based on four one-dimensional magnetic order parameters is developed and studied numerically. It is shown that coupling of the various order parameters leads to a complex magnetic field-temperature phase diagram and the results are compared to experiment.