Tunable thermal expansion in framework materials through redox intercalation.
Tunable thermal expansion in framework materials through redox intercalation.
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通过氧化还原插层调节框架材料的热膨胀
DOI：
10.1038/ncomms14441
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发表时间：
2017-02-09
影响因子：
16.6
通讯作者：
Xing X
中科院分区：
文献类型：
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作者：
Chen J;Gao Q;Sanson A;Jiang X;Huang Q;Carnera A;Rodriguez CG;Olivi L;Wang L;Hu L;Lin K;Ren Y;Lin Z;Wang C;Gu L;Deng J;Attfield JP;Xing X
固体的热膨胀特性是人们最关心的问题，控制热膨胀对实际应用很重要，但很难实现。许多框架型材料在内部笼空时表现为负热膨胀，而当额外的原子或分子填充内部空隙时表现为正热膨胀。在这里，我们发现氧化还原嵌入提供了一种有效的方法，通过将Li离子插入到简单的负热膨胀框架材料ScF3中，掺杂10%的铁以实现还原，从而控制热膨胀从正到零到负。小浓度的插层Li离子通过氟离子横向振动的空间位阻对氟离子横向振动有很强的影响，直接控制了热膨胀。因此，客体离子的氧化还原插入可能是控制许多已知的声子驱动负热膨胀的框架材料的热膨胀的一般和有效的方法。大多数材料在升高的温度下表现出的正热膨胀对于许多高精度应用来说是一个严重的问题。在这里，Xing和同事们表明，Li离子的氧化还原嵌入到ScF3框架中，可以有效地控制这种简单材料的热膨胀。
Thermal expansion properties of solids are of fundamental interest and control of thermal expansion is important for practical applications but can be difficult to achieve. Many framework-type materials show negative thermal expansion when internal cages are empty but positive thermal expansion when additional atoms or molecules fill internal voids present. Here we show that redox intercalation offers an effective method to control thermal expansion from positive to zero to negative by insertion of Li ions into the simple negative thermal expansion framework material ScF3, doped with 10% Fe to enable reduction. The small concentration of intercalated Li ions has a strong influence through steric hindrance of transverse fluoride ion vibrations, which directly controls the thermal expansion. Redox intercalation of guest ions is thus likely to be a general and effective method for controlling thermal expansion in the many known framework materials with phonon-driven negative thermal expansion. The positive thermal expansion exhibited by most materials at increased temperatures is a severe issue for many high precision applications. Here, Xing and co-workers show that redox intercalation of Li ions into a ScF3 framework offers effective control of the thermal expansion for this simple material.