弱いJahn-Teller d2cationにおける非常に安定した協同歪曲:ビクスバイトから高圧および高温変換により得られるペロブスキート型ScVO3
Elizabeth Castillo-Martínez1, Mario Bieringer, Shahid P Shafi
1Departamento de Química Inorgánica & Laboratorio Complutense de Altas Presiones, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain. ilaisza@hotmail.com
Journal of the American Chemical Society
|May 18, 2011
まとめ
新しいスカンジウムバナダート (ScVO(3)) ペロブスキート相が,高圧と高温で合成されました. この新しい素材は,ヤーン・テラー歪みと反鉄磁性順序を含むユニークな構造,電気,磁性特性を備えています.
科学分野:
- マテリアルサイエンス 材料科学
- 固体化学 固体化学
- クリスタログラフィーです.
背景:
- ペロブスキート酸化物は,様々な技術的な応用において極めて重要です.
- 新しいペロブスキットの構造-性質関係を理解することは,材料の開発に不可欠です.
- スカンジウムヴァナデート (ScVO(3)) は,複雑な相行動を示しています.
研究 の 目的:
- 新しい ScVO ((3) ペロブスキート相を合成し,特徴づけること.
- その構造的,電気的,磁気的性質を調査する.
- 合成条件がペロブスキート形成に及ぼす影響を理解する.
主な方法:
- 高圧・高温合成 (8 GPa,1073 K) について
- 室温および低温での構造分析のためのX線 difraktion.
- 電気伝導性の測定. 電気伝導性の測定. 電気伝導性の測定. 電気伝導性の測定. 電気伝導性の測定.
- 磁気感受性の測定. 磁気感受性の測定. 磁気感受性の測定. 磁気感受性の測定.
主要な成果:
- 新しいオーソロンビック ScVO(3) ペロブスキート相 (空間群 Pnma) が成功裏に合成されました.
- 構造は,オーダーされたSc(3+) とV(3+) イオンと協力的なJahn-Teller歪みを特徴としています.
- 電気伝導性はアーレニウス型行動に従っている.
- 90 K 近くで,三角対称性 (空間群 P-1) に構造的移行が起こります.
- ヴァナジウム磁気モメントの反鉄磁気長距離オーダーリングは60K以下で観察され,特定の磁気上の構造を形成します.
結論:
- 新しい ScVO(3) ペロブスキート相の合成は,ヴァナドート材料の既知の風景を拡大する.
- 観測されたヤーン・テラー歪みと磁気順序は,構造と電子特性との複雑な相互作用を強調しています.
- この材料は,特定の磁気および電気的特性を要求する分野におけるさらなる調査の可能性を提示しています.
関連する概念動画
Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
Imperfections in Crystal Structure: Non-Stoichiometric Defects
Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...
Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Stability of Equilibrium Configuration
Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable.
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.


