Nanocrystals with metastable high-pressure phases under ambient conditions
Nanocrystals with metastable high-pressure phases under ambient conditions
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DOI：
10.1126/science.abq7684
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发表时间：
2022-08
期刊：
影响因子：
56.9
通讯作者：
Tianyuan Xiao;Yasutaka Nagaoka;Xirui Wang;Tian Jiang;D. LaMontagne;Qiang Zhang;C. Cao;Xizheng Diao;Jiahua Qiu;Yiruo Lu;Zhongwu Wang;Y. C. Cao
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文献类型：
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作者：
Tianyuan Xiao;Yasutaka Nagaoka;Xirui Wang;Tian Jiang;D. LaMontagne;Qiang Zhang;C. Cao;Xizheng Diao;Jiahua Qiu;Yiruo Lu;Zhongwu Wang;Y. C. Cao
环境亚稳性的岩盐相在定义良好的模型系统，包括纳米球或纳米棒的硒化镉，硫化镉，或两者的组成，初始晶相，颗粒结构，形状，表面功能化，和有序的组装水平的函数进行了研究。我们的实验表明，这些体系在岩盐到锌盐的固相转变中表现出配体可剪裁的可逆性。颗粒间烧结被用来设计相变中的动力学障碍，以可控的方式产生常压亚稳态岩盐结构。互联的网络被认为是一个重要的结构，托管亚稳态高能量相在环境条件下。这些研究结果表明，一般规则的转换屏障工程，是有用的下一代材料的合理设计。描述配体驱动的亚稳态如果存在动力学障碍，固体的高压相可以在环境压力下持续存在。Xiao等人在良好控制的纳米球或纳米棒的硒化镉、硫化镉或两者的模型系统中，对四到六坐标压力驱动的固相转变的可逆性进行了详细的机理研究（参见Mao和Lin的观点）。表面配体的选择可以控制转化的可逆性。颗粒间烧结有助于消除晶体缺陷和放松高压岩盐结构的晶格畸变，以保持其环境压力亚稳性。-PDS颗粒间烧结可以在环境条件下稳定硒化镉和硫化镉纳米网络的高压相。
The ambient metastability of the rock-salt phase in well-defined model systems comprising nanospheres or nanorods of cadmium selenide, cadmium sulfide, or both was investigated as a function of composition, initial crystal phase, particle structure, shape, surface functionalization, and ordering level of their assemblies. Our experiments show that these nanocrystal systems exhibit ligand-tailorable reversibility in the rock salt–to–zinc blende solid-phase transformation. Interparticle sintering was used to engineer kinetic barriers in the phase transformation to produce ambient-pressure metastable rock-salt structures in a controllable manner. Interconnected nanocrystal networks were identified as an essential structure that hosted metastable high-energy phases at ambient conditions. These findings suggest general rules for transformation-barrier engineering that are useful in the rational design of next-generation materials. Description Ligand-driven metastability A high-pressure phase of a solid can persist at ambient pressure if there are kinetic barriers to its relaxation. Xiao et al. performed detailed mechanistic studies on the reversibility of four- to six-coordinate pressure-driven solid-phase transitions in well-controlled model systems of nanospheres or nanorods of cadmium selenide, cadmium sulfide, or both (see the Perspective by Mao and Lin). The choice of surface ligands could control the reversibility of the transformations. Interparticle sintering helped to eliminate crystal defects and relaxed lattice distortions from the high-pressure rock-salt structures to maintain their ambient-pressure metastability. —PDS Interparticle sintering can stabilize high-pressure phases of cadmium selenide and cadmium sulfide nanocrystal networks at ambient conditions.