Trimers of MnO6 octahedra and ferrimagnetism of Ba4NbMn3O12

TL;DR

This paper reports the synthesis, crystal structure, magnetic properties, and semiconducting behavior of Ba4NbMn3O12, which features Mn3O12 trimers and exhibits ferrimagnetism around 42 K.

Contribution

It provides the first detailed characterization of Ba4NbMn3O12, revealing its unique trimer-based structure and ferrimagnetic ordering, expanding understanding of magnetic interactions in Mn-based oxides.

Findings

Contains Mn3O12 trimers with face-sharing MnO6 octahedra.

Exhibits ferrimagnetic ordering at approximately 42 K.

Shows semiconducting behavior with a transport activation energy of 0.37 eV.

Abstract

Ba4NbMn3O12 is reported, synthesized by a solid state method in air. The crystal structure, determined by performing refinements on room temperature powder X-ray diffraction data by the Rietveld method, consists of Mn3O12 trimers in the configuration of three face-sharing MnO6 octahedra, with the trimers arranged in triangular planes. An effective moment of 4.82 {\mu}B/f.u is observed and competing antiferromagnetic and ferromagnetic interactions between Mn ions are inferred from the Weiss temperature of -4 K and the ferrimagnetic ordering transition of approximately 42 K. Ba4NbMn3O12 is a semiconductor with a transport activation energy of 0.37 eV.