Magnetic properties of metal-organic coordination networks based on 3d transition metal atoms
Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；Paul Scherrer Institute（保罗谢尔研究所）；IKERBASQUE, Basque Foundation for Science（伊克尔巴斯基克科学基金会）；Tomsk State University（托木斯克州立大学）；Saint Petersburg State University（圣彼得堡国立大学）
María Blanco-Rey, Ane Sarasola, Corneliu Nistor, Luca Persichetti, Christian Stamm, Cinthia Piamonteze, Pietro Gambardella, Sebastian Stepanow, Mikhail M. Otrok… 展开作者
María Blanco-Rey, Ane Sarasola, Corneliu Nistor, Luca Persichetti, Christian Stamm, Cinthia Piamonteze, Pietro Gambardella, Sebastian Stepanow, Mikhail M. Otrokov, Vitaly N. Golovach, Andres Arnau
备注：
17 pages, 7 figures, submitted to Molecules (MDPI) on February 21st 2018, Supplementary Material in submit/2172866
The magnetic anisotropy and exchange coupling between spins localized at the positions of 3d transition metal atoms forming two-dimensional metal-organic coordination networks (MOCNs) grown on the Au(111) metal surface are studied. In particular, we consider MOCNs made of Ni or Mn metal centers linked by TCNQ (7,7,8,8-tetracyanoquinodimethane) organic ligands, which form rectangular networks with 1:1 stoichiometry. Based on the analysis of X-ray magnetic circular dichroism (XMCD) data taken at T= 2.5 K, we find that Ni atoms in the Ni-TCNQ MOCNs are coupled ferromagnetically and do not show any significant magnetic anisotropy, while Mn atoms in the Mn-TCNQ MOCNs are coupled antiferromagnetically and do show a weak magnetic anisotropy with in-planemagnetization. We explain these observations using both amodelHamiltonian based on mean-fieldWeiss theory and density functional theory calculations that include spin-orbit coupling. Our main conclusion is that the antiferromagnetic coupling between Mn spins and the in-plane magnetization of the Mn spins can be explained neglecting effects due to the presence of the Au(111) surface, while for Ni-TCNQ the metal surface plays a role in determining the absence of magnetic anisotropy in the system.
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Observation of Anderson localization transitions in a two-dimensional conjugated metal-organic framework
Tianjin University（天津大学）；Key Laboratory of Organic Integrated Circuits, Ministry of Education（教育部有机集成电路重点实验室）；Tianjin Key Laboratory of Molecular Optoelectronic Sciences（天津市分子光电科学重点实验室）；Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)（（天津）化工过程与先进制造国家重点实验室协同创新中心）；Center for Joint Quantum Studies（联合量子研究中心）；Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology（天津市低维材料物理与制备技术重点实验室）
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