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B-Site-Ordered and Disordered Structures in A-Site-Ordered Quadruple Perovskites RMn3Ni2Mn2O12 with R = Nd, Sm, Gd,
Alexei A Belik1, Ran Liu1,2,3, Masahiko Tanaka4
1Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba 305-0044, Ibaraki, Japan.
Molecules (Basel, Switzerland)
|December 17, 2024
Summary
This study synthesized A-site-ordered quadruple perovskites (RMn3Ni2Mn2O12) using high pressure. Magnetic properties were similar regardless of B-site ordering, unlike related double perovskites.
Area of Science:
- Materials Science
- Solid State Chemistry
- Magnetism
Background:
- Perovskite materials with small A-site cations exhibit unique physical properties.
- A-site ordering in perovskites leads to deviations from typical behavior.
- Understanding cation ordering effects on magnetic properties is crucial.
Purpose of the Study:
- To synthesize and characterize A-site-ordered quadruple perovskites RMn3Ni2Mn2O12.
- To investigate the influence of B-site ordering (Ni2+ and Mn4+) on magnetic properties.
- To compare magnetic behavior with related double perovskites.
Main Methods:
- High-pressure, high-temperature synthesis (approx. 6 GPa).
- Annealing treatments at different temperatures (1500 K and 1700 K) to control B-site ordering.
- X-ray diffraction to determine crystal structure (space groups Pn-3 and Im-3).
- Magnetic property measurements, including magnetic transitions and Curie-Weiss temperatures.
Main Results:
- Successfully synthesized RMn3Ni2Mn2O12 (R = Nd, Sm, Gd, Dy) perovskites.
- Partial B-site ordering (Ni2+/Mn4+) observed at 1500 K (Pn-3), disorder at 1700 K (Im-3).
- Magnetic properties were nearly identical for both ordered and disordered B-site structures.
- Identified magnetic transitions at low temperatures (22-36 K) and near-zero Curie-Weiss temperatures.
Conclusions:
- B-site cation ordering (Ni2+/Mn4+) has minimal impact on the magnetic properties of these quadruple perovskites.
- The magnetic interactions in RMn3Ni2Mn2O12 are a balance of ferromagnetic and antiferromagnetic forces.
- These findings contrast with double perovskites where B-site ordering significantly affects magnetism.
Keywords:
A-site-ordered quadruple perovskitesB-site double orderingcrystal structuresstructural disorderMore Related Videos
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