Orbital ordering and enhanced magnetic frustration of strained BiMnO3 thin films

TL;DR

This study investigates how epitaxial strain influences orbital ordering and magnetic frustration in BiMnO3 thin films, revealing enhanced magnetic frustration and cluster-glass behavior due to strain-induced orbital order.

Contribution

It demonstrates strain-induced orbital ordering and magnetic frustration in BiMnO3 thin films, a phenomenon not observed in bulk material.

Findings

Orbital order detected at wave vector (1/4 1/4 1/4).

Strain enhances magnetic frustration leading to cluster-glass-like properties.

Bulk BiMnO3 exhibits simple ferromagnetism, unlike strained films.

Abstract

Epitaxial thin films of multiferroic perovskite BiMnO3 were synthesized on SrTiO3 substrates, and orbital ordering and magnetic properties of the thin films were investigated. The ordering of the Mn^{3+} e_g orbitals at a wave vector (1/4 1/4 1/4) was detected by Mn K-edge resonant x-ray scattering. This peculiar orbital order inherently contains magnetic frustration. While bulk BiMnO3 is known to exhibit simple ferromagnetism, the frustration enhanced by in-plane compressive strains in the films brings about cluster-glass-like properties.