Parreiras Sofia O, Moreno Daniel, Cirera Borja, Valbuena Miguel A, Urgel José I, Paradinas Markos, Panighel Mirco, Ajejas Fernando, Niño Miguel A, Gallego José M, Valvidares Manuel, Gargiani Pierluigi, Kuch Wolfgang, Martínez José I, Mugarza Aitor, Camarero Julio, Miranda Rodolfo, Perna Paolo, Écija David
Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanoscience), Madrid, 28049, Spain.
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, Barcelona, 08193, Spain.
Small. 2021 Sep;17(35):e2102753. doi: 10.1002/smll.202102753. Epub 2021 Jul 18.
Taming the magnetic anisotropy of lanthanides through coordination environments is crucial to take advantage of the lanthanides properties in thermally robust nanomaterials. In this work, the electronic and magnetic properties of Dy-carboxylate metal-organic networks on Cu(111) based on an eightfold coordination between Dy and ditopic linkers are inspected. This surface science study based on scanning probe microscopy and X-ray magnetic circular dichroism, complemented with density functional theory and multiplet calculations, reveals that the magnetic anisotropy landscape of the system is complex. Surface-supported metal-organic coordination is able to induce a change in the orientation of the easy magnetization axis of the Dy coordinative centers as compared to isolated Dy atoms and Dy clusters, and significantly increases the magnetic anisotropy. Surprisingly, Dy atoms coordinated in the metallosupramolecular networks display a nearly in-plane easy magnetization axis despite the out-of-plane symmetry axis of the coordinative molecular lattice. Multiplet calculations highlight the decisive role of the metal-organic coordination, revealing that the tilted orientation is the result of a very delicate balance between the interaction of Dy with O atoms and the precise geometry of the crystal field. This study opens new avenues to tailor the magnetic anisotropy and magnetic moments of lanthanide elements on surfaces.
通过配位环境调控镧系元素的磁各向异性对于在热稳定纳米材料中利用镧系元素的性质至关重要。在这项工作中，基于Dy与双齿连接体之间的八重配位，研究了Cu(111)表面上Dy-羧酸盐金属有机网络的电子和磁性质。这项基于扫描探针显微镜和X射线磁圆二色性的表面科学研究，辅以密度泛函理论和多重态计算，揭示了该体系的磁各向异性情况复杂。与孤立的Dy原子和Dy簇相比，表面支撑的金属有机配位能够引起Dy配位中心易磁化轴方向的变化，并显著增加磁各向异性。令人惊讶的是，尽管配位分子晶格具有面外对称轴，但在金属超分子网络中配位的Dy原子却显示出近乎面内的易磁化轴。多重态计算突出了金属有机配位的决定性作用，表明倾斜取向是Dy与O原子相互作用和晶体场精确几何结构之间非常微妙平衡的结果。这项研究为调控表面镧系元素的磁各向异性和磁矩开辟了新途径。
