Gambardella Pietro, Stepanow Sebastian, Dmitriev Alexandre, Honolka Jan, de Groot Frank M F, Lingenfelder Magalí, Sen Gupta Subhra, Sarma D D, Bencok Peter, Stanescu Stefan, Clair Sylvain, Pons Stéphane, Lin Nian, Seitsonen Ari P, Brune Harald, Barth Johannes V, Kern Klaus
Centre d'Investigacions en Nanociència i Nanotecnologia (ICN-CSIC), UAB Campus, E-08193 Barcelona, Spain.
Nat Mater. 2009 Mar;8(3):189-93. doi: 10.1038/nmat2376. Epub 2009 Feb 1.
Magnetic atoms at surfaces are a rich model system for solid-state magnetic bits exhibiting either classical or quantum behaviour. Individual atoms, however, are difficult to arrange in regular patterns. Moreover, their magnetic properties are dominated by interaction with the substrate, which, as in the case of Kondo systems, often leads to a decrease or quench of their local magnetic moment. Here, we show that the supramolecular assembly of Fe and 1,4-benzenedicarboxylic acid molecules on a Cu surface results in ordered arrays of high-spin mononuclear Fe centres on a 1.5 nm square grid. Lateral coordination with the molecular ligands yields unsaturated yet stable coordination bonds, which enable chemical modification of the electronic and magnetic properties of the Fe atoms independently from the substrate. The easy magnetization direction of the Fe centres can be switched by oxygen adsorption, thus opening a way to control the magnetic anisotropy in supramolecular layers akin to that used in metallic thin films.
表面的磁性原子是一个丰富的固态磁位模型系统，展现出经典或量子行为。然而，单个原子难以排列成规则图案。此外，它们的磁性主要由与基底的相互作用主导，就像在近藤系统中一样，这常常导致其局部磁矩减小或淬灭。在此，我们表明，铁原子与1,4 - 苯二甲酸分子在铜表面的超分子组装形成了在1.5纳米方格上的高自旋单核铁中心有序阵列。与分子配体的横向配位产生了不饱和但稳定的配位键，这使得铁原子的电子和磁性性质能够独立于基底进行化学修饰。铁中心的易磁化方向可通过氧吸附来切换，从而开辟了一种类似于金属薄膜中使用的方法来控制超分子层中磁各向异性的途径。
