Coexistence of ferromagnetism and metallic conductivity in a molecule-based layered compound
Coexistence of ferromagnetism and metallic conductivity in a molecule-based layered compound
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DOI：
10.1038/35044035
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发表时间：
2000-11-23
期刊：
影响因子：
64.8
通讯作者：
Laukhin, V
中科院分区：
文献类型：
--
作者：
Coronado, E;Galán-Mascarós, JR;Laukhin, V
晶体工程-从模块化构建块规划和构建晶体超分子结构-允许合理设计功能分子材料，这些材料表现出技术上有用的行为，如导电性和超导性（1），铁磁性（2）和非线性光学性质（3）。由于在同一晶格中存在两种协同性质可能导致新的物理现象和新的应用，一个特别吸引人的目标是设计具有两种性质的分子材料，这两种性质在具有连续晶格的常规无机固体中难以或不可能联合收割机结合。一个有前途的策略，用于创建这种类型的“双功能”的目标混合有机/无机晶体，包括两个功能的子晶格表现出不同的性能。以这种方式，有机π电子给体双（亚乙基二硫代）四硫富瓦烯（BEDT-TTF）及其衍生物，形成了最已知的分子导体和超导体（1）的基础，已与分子磁性阴离子结合，主要产生具有常规半导体或导电性能的材料（4，5），但也是超导和顺磁的系统（6，7）。但是，由于无机阴离子的离散性质，有趣的大块磁性未能发展。实现协同磁性的另一种策略涉及将功能性大体积阳离子插入到聚合磁性阴离子中，例如双金属络合物[（MnCrIII）-Cr-II（C2 O 4）（3）]（-），但在大多数情况下仅获得不溶性粉末（8-12）。在这里，我们报告的单晶体的合成形成的无限片的这种磁性配位聚合物交错层的导电BEDT-TTF阳离子，并表明，这种分子为基础的化合物显示铁磁性和金属导电性。
Crystal engineering-the planning and construction of crystalline supramolecular architectures from modular building blocks-permits the rational design of functional molecular materials that exhibit technologically useful behaviour such as conductivity and superconductivity(1), ferromagnetism(2) and nonlinear optical properties(3). Because the presence of two cooperative properties in the same crystal lattice might result in new physical phenomena and novel applications, a particularly attractive goal is the design of molecular materials with two properties that are difficult or impossible to combine in a conventional inorganic solid with a continuous lattice. A promising strategy for creating this type of 'bi-functionality' targets hybrid organic/inorganic crystals comprising two functional sub-lattices exhibiting distinct properties. In this way, the organic pi -electron donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and its derivatives, which form the basis of most known molecular conductors and superconductors(1), have been combined with molecular magnetic anions, yielding predominantly materials with conventional semiconducting or conducting properties(4,5), but also systems that are both superconducting and paramagnetic(6,7). But interesting bulk magnetic properties fail to develop, owing to the discrete nature of the inorganic anions. Another strategy for achieving cooperative magnetism involves insertion of functional bulky cations into a polymeric magnetic anion, such as the bimetallic oxalato complex [(MnCrIII)-Cr-II (C2O4)(3)](-), but only insoluble powders have been obtained in most cases(8-12). Here we report the synthesis of single crystals formed by infinite sheets of this magnetic coordination polymer interleaved with layers of conducting BEDT-TTF cations, and show that this molecule-based compound displays ferromagnetism and metallic conductivity.