Neutron diffraction studies and the magnetism of an ordered perovskite: Ba2CoTeO6

TL;DR

This study synthesizes Ba2CoTeO6, revealing its crystal structure and antiferromagnetic order at 15 K through neutron diffraction and other measurements, and compares it with similar Co-based perovskites.

Contribution

It provides detailed structural and magnetic characterization of Ba2CoTeO6, including its long-range antiferromagnetic order and unique structural features.

Findings

Ba2CoTeO6 adopts a 6L-trigonal perovskite structure.

Antiferromagnetic order observed below 15 K.

Structural features compared with other Co-based perovskites.

Abstract

The complex perovskite Ba2CoTeO6 (BCTO) has been synthesised, and the crystal structure and magnetic properties have been investigated using a combination of X-ray and neutron powder diffraction, electron microscopy and dielectric, calorimetric and magnetic measurements. It was shown that at room temperature this compound adopts the 6L-trigonal perovskite structure, space group P-3m (N 164) (a= 5.7996(1){\AA}, c=14.2658(3){\AA}). The structure comprises dimers of face-sharing octahedra as well as octahedra which share only vertices with their neighbours. A long-range antiferromagnetically ordered state has been identified from neutron diffraction and magnetic studies. The magnetic diffraction peaks were registered below the magnetic transition at about 15 K and a possible model for the magnetic structure is proposed. The structural and magnetic features of this compound are discussed and compared with those of other Co-based quaternary oxides adopting the perovskite structure.