電子構造,磁気順序,および移行金属酸化物ヒドリドLaSrCoO ((3) H ((0.7) の形成経路
Craig A Bridges1, George R Darling, Michael A Hayward
1Department of Chemistry, The University of Liverpool, Liverpool L69 7ZD, UK.
Journal of the American Chemical Society
|April 21, 2005
まとめ
水素アニオンは,ランタン・ストロンチウム・コバルト酸化水素 (LaSrCoO3H0.7) の電子特性に大きな影響を与える. 場所でのX線 difraktionは,水素の組み込みメカニズムと中間組成の洞察を明らかにします.
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
- コンピューティング・マテリアル・サイエンス・サイエンス
背景:
- 移行金属酸化水素は,調節可能な電子および磁気特性を有する有望な材料です.
- 水素の役割を理解することは,新しい酸化水素材料の設計に不可欠です.
研究 の 目的:
- LaSrCoO3H0.7の電子特性を調査し,ヒドリドアニオンの影響に焦点を当てました.
- 酸化水素構造に水素を組み込むメカニズムを解明する.
- 磁気オーダー温度 (ニール温度) を決定する.
主な方法:
- フルポテンシャル密度関数理論 (DFT) バンド構造の計算.
- ニール温度を実験的に測定する.
- 酸化水酸化物形成中のX線 difraktion in situの研究.
主要な成果:
- ハイドリドアニオンは,LaSrCoO3H0.7.7.の電子特性を制御する上で重要な役割を果たしています.
- In situ XRDの研究では,酸化水素順序とアニゾトロピック difraktion プロフィール拡大の間の関係が明らかになりました.
- 形成過程で,一連の中間組成物が特定されました.
結論:
- この研究は,LaSrCoO3H0.7.7.の電子および磁気特性に関する理論的および実験的洞察を提供します.
- この発見は,移行金属酸化物ヒドリドの合成における水素組み込みメカニズムの重要性を強調しています.
関連する概念動画
02:48Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:58Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
02:42Valence 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...
02:58Crystal 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...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.