B-Site-Ordered and Disordered Structures in A-Site-Ordered Quadruple Perovskites RMn<sub>3</sub>Ni<sub>2</sub>Mn<sub>2</sub>O<sub>12</sub> with R = Nd, Sm, Gd, and Dy

B-Site-Ordered and Disordered Structures in A-Site-Ordered Quadruple Perovskites RMn<sub>3</sub>Ni<sub>2</sub>Mn<sub>2</sub>O<sub>12</sub> with R = Nd, Sm, Gd, and Dy

ABO<sub>3</sub> perovskite materials with small cations at the A site, especially with ordered cation arrangements, have attracted a lot of interest because they show unusual physical properties and deviations from general perovskite tendencies. In this work, A-site-ordered quadruple per...

Full description

Saved in:
Bibliographic Details
Main Authors: Alexei A. Belik, Ran Liu, Masahiko Tanaka, Kazunari Yamaura
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Molecules
Subjects:
A-site-ordered quadruple perovskites
B-site double ordering
crystal structures
structural disorder
Online Access:https://www.mdpi.com/1420-3049/29/23/5488
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABO<sub>3</sub> perovskite materials with small cations at the A site, especially with ordered cation arrangements, have attracted a lot of interest because they show unusual physical properties and deviations from general perovskite tendencies. In this work, A-site-ordered quadruple perovskites, RMn<sub>3</sub>Ni<sub>2</sub>Mn<sub>2</sub>O<sub>12</sub> with R = Nd, Sm, Gd, and Dy, were synthesized by a high-pressure, high-temperature method at about 6 GPa. Annealing at about 1500 K produced samples with additional (partial) B-site ordering of Ni<sup>2+</sup> and Mn<sup>4+</sup> cations, crystallizing in space group <i>Pn</i>–3. Annealing at about 1700 K produced samples with disordering of Ni<sup>2+</sup> and Mn<sup>4+</sup> cations, crystallizing in space group <i>Im</i>–3. However, magnetic properties were nearly identical for the <i>Pn</i>–3 and <i>Im</i>–3 modifications in comparison with ferromagnetic double perovskites R<sub>2</sub>NiMnO<sub>6</sub>, where the degree of Ni<sup>2+</sup> and Mn<sup>4+</sup> ordering has significant effects on magnetic properties. In RMn<sub>3</sub>Ni<sub>2</sub>Mn<sub>2</sub>O<sub>12</sub>, one magnetic transition was found at 26 K (for R = Nd), 23 K (for R = Sm), and 22 K (for R = Gd), and two transitions were found at 10 K and 36 K for R = Dy. Curie–Weiss temperatures were close to zero in all compounds, suggesting that antiferromagnetic and ferromagnetic interactions are of the same magnitude.
ISSN:1420-3049

Similar Items