Zeng Qingxin, Wang Kai, Qiao Yuancun, Li Xiaodong, Zou Bo
State Key Laboratory of Superhard Materials, Jilin University , Changchun 130012, China.
Beijing Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100039, China.
J Phys Chem Lett. 2017 Apr 6;8(7):1436-1441. doi: 10.1021/acs.jpclett.7b00121. Epub 2017 Mar 17.
Negative linear compressibility (NLC) is a rare and counterintuitive phenomenon because materials with this property would expand along one specific direction when uniformly compressed. NLC materials have a broad range of potential applications in designing pressure sensors, artificial muscles, and so on. Designing and searching for systems with NLC is desired and crucial for material and compression science. Herein, with the help of high-pressure X-ray diffraction measurements and density functional theory calculations, we find that the 2D layered Co(SCN)(pyrazine) exhibits NLC with a new mechanism: layer sliding. When compressed, the ab planes slide along the a axis, leading to the decrease of lattice parameter β, which results in the NLC effect along principal axis X (≈ -0.84a - 0.55c). The layer sliding mechanism opens exciting opportunities for seeking, designing, and synthesizing new classes of materials with anomalous mechanical properties in monoclinic layered or other related systems.
负线性压缩性（NLC）是一种罕见且违反直觉的现象，因为具有这种特性的材料在均匀压缩时会沿一个特定方向膨胀。NLC材料在设计压力传感器、人造肌肉等方面具有广泛的潜在应用。设计和寻找具有NLC的系统对于材料和压缩科学来说是必要且至关重要的。在此，借助高压X射线衍射测量和密度泛函理论计算，我们发现二维层状Co(SCN)(吡嗪)呈现出一种具有新机制的NLC：层滑动。当被压缩时，ab平面沿a轴滑动，导致晶格参数β减小，这就产生了沿主轴X（≈ -0.84a - 0.55c）的NLC效应。层滑动机制为在单斜层状或其他相关体系中寻找、设计和合成具有异常力学性能的新型材料开辟了令人兴奋的机会。
