Construction of a two-dimensional metal-organic framework with perpendicular magnetic anisotropy composed of single-molecule magnets
Construction of a two-dimensional metal-organic framework with perpendicular magnetic anisotropy composed of single-molecule magnets
复制标题
由单分子磁体组成的具有垂直磁各向异性的二维金属有机骨架的构建
DOI：
10.1039/d2tc04963e
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发表时间：
2023
影响因子：
6.4
通讯作者：
Kajiwara Takashi
中科院分区：
文献类型：
--
作者：
Aratani Ikumi;Horii Yoji;Takajo Daisuke;Kotani Yoshinori;Osawa Hitoshi;Kajiwara Takashi
使用单分子磁体(SMM)作为存储器件可以极大地增加信息存储容量。然而，需要在衬底上构建规则的SMM阵列以访问单个SMM。到目前为止，已经报道了各种方法来实现SMM的二维集成，如自组装单分子膜、Langmuir-Blodgett(LB)方法、气相沉积和封装到金属-有机骨架(MOF)中。在这里，我们报道了一种基于气液界面形成配位键来构建SMM纳米片的新方法。合成了一种以四个吡啶单元取代的酞菁-卟啉Tb(III)双层SMM，并与Pd~(2+)在气-水界面上发生反应。形成的MOF具有良好的力学性能和垂直磁各向异性，在信息存储领域具有广阔的应用前景。相反，由于SMM的无序排列，不含Pd2+的薄膜表现出面内磁各向异性。此外，与Pd2+离子的反应增加了高温区的磁弛豫时间。从SMM的高浓度、结构规则性和可设计性以及衬底选择的通用性的角度来看，我们的制备SMM纳米片的策略与以前的方法相比是有前景的。
The use of single-molecule magnets (SMMs) as memory devices can dramatically increase information storage capacity. However, a regular array of SMMs needs to be constructed on a substrate to access individual SMMs. Various approaches for integrating SMMs two-dimensionally, such as self-assembled monolayers, Langmuir–Blodgett (LB) methods, vapor deposition, and encapsulation into metal–organic frameworks (MOFs), have been reported so far. Herein, we report a new method for constructing SMM nanosheets based on the formation of coordination bonds at the air–liquid interface. A phthalocyaninato-porphyrinato terbium(III) double-decker SMM substituted with four pyridyl units was synthesized and reacted with Pd2+ ions at the air–water interface. The formed MOF was mechanically robust and exhibited perpendicular magnetic anisotropy, which is promising for use in information storage. In contrast, the thin film formed without Pd2+ exhibited in-plane magnetic anisotropy owing to the disordered arrangement of SMMs. Furthermore, the reaction with Pd2+ ions increased the magnetic relaxation times in the high-temperature region. Our strategy for making the SMM nanosheet is promising compared with the previous method from the viewpoint of the high concentration of SMMs, structural regularity and designability, and versatility of substrate selection.