Mn$_2$FeSbO$_6$: a ferrimagnetic ilmenite and an antiferromagnetic perovskite

TL;DR

This paper explores the polymorphic nature of Mn$_2$FeSbO$_6$, which can be synthesized as either a ferrimagnetic ilmenite or an antiferromagnetic perovskite, detailing their structures and magnetic properties.

Contribution

It provides a detailed analysis of the structural phase transformation and proposes magnetic structures for both polymorphs, highlighting the rare perovskite form with Mn on the $A$-site.

Findings

High-pressure synthesis yields a rare Mn-based perovskite

Distinct magnetic structures for ilmenite and perovskite phases

Perovskite phase exhibits complex magnetic order and electronic polarization

Abstract

Due of its polymorphism, Mn$_2$FeSbO$_6$ can be synthesized at high pressures and temperatures as a ferrimagnetic ilmenite or an antiferromagnetic perovskite. The structural phase transformation is discussed in detail, and magnetic structures are proposed for both phases. The high-pressure Mn$_2$FeSbO$_6$ polymorph is a rare example of $A_2 B'B"$O$_6$ perovskite with solely Mn cations on the $A$-site. Fe and Sb cations are ordered on the $B$-sites. Theoretical calculations for the perovskite phase suggest a complex magnetic structure, holding an electronic polarization.