Fe(II) キューブの磁性アニソトロピーの制御に向けて:DFTの研究
Jordi Ribas-Arino1, Tunna Baruah, Mark R Pederson
1Departament de Química Física, Facultat de Química i Centre Especial de Recerca en Química Teórica, Parc Científic, Universitat de Barcelona, Av. Diagonal 647, Barcelona 08028, Spain. jribasjr@yahoo.es
Journal of the American Chemical Society
|July 20, 2006
まとめ
密度関数計算により,鉄複合体における磁性アニソトロピーが明らかになった. 一つの複合体は単一分子磁石として作用し,その磁気アニソトロピーバリアを強化する規則が提案されています.
科学分野:
- * コンピュータ化学
- * * 材料科学は材料科学である.
- * マグネティズム (磁気)
背景:
- *多核鉄複合体は磁気特性のために研究されています.
- *磁性アニソトロピーの理解は,単分子磁石 (SMM) の開発に不可欠です.
研究 の 目的:
- *全電子密度関数計算を用いて[Fe4(sap) 4 ((MeOH) 4)) と[Fe4 ((sae) 4 ((MeOH) 4)) ]複合体の磁性アニソトロピーを調査する.
- * これらの鉄複合体の磁気行動に影響を与える要因を理解する.
- * 類似のシステムにおける磁性アニソトロピーバリアを強化するための戦略を提案する.
主な方法:
- * 全電子密度関数計算を行った.
- *個々のFe (II) イオンの予測磁性アニソトロピーの分析.
- * D値が幾何学的なパラメータに依存しているかを研究する.
- * 予測ルールを導き出すための分子軌道分析.
主要な成果:
- * [Fe4 (sae) 4 (MeOH) 4) ]は,磁性アニソトロピーのエネルギーバリアが5.6Kの単分子磁石として機能することを計算で予測しています.
- * 予測された行動は,実験データと質的に一致する.
- * 磁性アニソトロピーバリアを約6倍に高めるルールが開発されました.
- *高スピンのFe (II) イオンでは,局所的な磁気化の容易軸は,二重に占有されているFe (II) -d軌道面に垂直である.
結論:
- *この研究は,多核鉄複合体の磁性アニソトロピーに関する洞察を提供します.
- * 磁性アニソトロピーバリアを強化するための予測ルールが確立され,SMMの合理的な設計の可能性が提供されました.
- *さらなる研究は,これらの発見を他の金属イオンに拡張し,磁気材料に合わせた合成戦略を可能にすることができます.
さらに関連する動画
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
07:42Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
関連する概念動画
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...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
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.
01:26Diamagnetism
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
01:31Ferromagnetism
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
01:31Magnetic Susceptibility and Permeability
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...