Strain-Controlled Spin Transition in Heterostructured Metal-Organic Framework Thin Film
Strain-Controlled Spin Transition in Heterostructured Metal-Organic Framework Thin Film
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DOI：
10.1021/jacs.1c06662
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发表时间：
2021-09-13
影响因子：
15
通讯作者：
Kitagawa, Hiroshi
中科院分区：
文献类型：
--
作者：
Haraguchi, Tomoyuki;Otsubo, Kazuya;Kitagawa, Hiroshi
金属有机骨架(MOF)薄膜作为一种新的表面/界面研究平台，近年来备受关注，出现了非常规的结构和物理性质。在众多制备薄膜的MOF中，Hofmann型MOF{Fe(Pz)[M(CN)(4)]}[Pz=吡嗪；M=Ni(Nipz)，M=Pt(Ptpz)]是很有吸引力的，因为它们经历了伴随着结构变化的自旋转变。在这里，我们展示了异质结构MOF薄膜中应变控制的自旋转变的第一个例子。通过制备具有Nipz缓冲层的纳米异质结构薄膜，可以将Ptpz的自旋转变温度控制在300-380K的温度范围内，其中较小的Nipz晶格对Ptpz层产生外延压缩应变。变温X射线衍射和变温拉曼光谱表明，制备的异质结薄膜的自旋转变温度显著提高，结构发生了动态转变。通过验证异质结构薄膜中的界面应变，我们可以合理地控制MOF的特性，不仅可以控制自旋跃迁，还可以控制各种物理性质，如储气、催化、传感、质子电导和电学性质等。
Metal-organic framework (MOF) thin films have recently attracted much attention as a new platform for surface/interface research, where unconventional structural and physical properties emerge. Among the many MOFs as candidates for fabrication of thin films, Hofmann-type MOFs {Fe(pz)[M(CN)(4)]} [pz = pyrazine; M = Ni (Nipz), M = Pt (Ptpz)] are attractive, because they undergo spin transitions with concomitant structural changes. Here, we demonstrate the first example of a strain-controlled spin transition in heterostructured MOF thin films. The spin transition temperature of Ptpz can be controlled in the temperature range of 300-380 K by fabricating a nanometer-sized heterostructured thin film with a Nipz buffer layer, where the smaller lattice of Nipz causes epitaxial compressive strain to the Ptpz layer. The fabricated heterostructured thin film exhibited a remarkable increase in spin transition temperature with a dynamic structural transformation, confirmed by variable-temperature (VT) X-ray diffraction and VT Raman spectroscopy. By verifying interfacial strain in a heterostructured thin film, we can rationally control the characteristics of MOFs.not only spin transition but also various physical properties such as gas storage, catalysis, sensing, proton conductivity, and electrical properties, among others.