Jiang Xingxing, Zhang Shengzi, Jiang Dequan, Wang Yonggang, Molokeev Maxim S, Wang Naizheng, Liu Youquan, Zhang Xingyu, Lin Zheshuai
New Functional Crystals Group, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Natl Sci Rev. 2023 Jan 20;10(9):nwad016. doi: 10.1093/nsr/nwad016. eCollection 2023 Sep.
Negative area compressibility (NAC) is a counterintuitive 'squeeze-expand' behavior in solids that is very rare but attractive due to possible pressure-response applications and coupling with rich physicochemical properties. Herein, NAC behavior is reported in palladium diselenide with a large magnitude and wide pressure range. We discover that, apart from the rigid flattening of layers that has been generally recognized, the unexpected giant NAC effect in PdSe largely comes from anomalous elongation of intralayer chemical bonds. Both structural variations are driven by intralayer-to-interlayer charge transfer with enhanced interlayer interactions under pressure. Our work updates the mechanical understanding of this anomaly and establishes a new guideline to explore novel compression-induced properties.
负面积压缩性（NAC）是固体中一种违反直觉的“挤压-膨胀”行为，这种行为非常罕见，但由于其在压力响应应用方面的潜力以及与丰富物理化学性质的耦合而备受关注。在此，我们报道了在二硒化钯中观察到的具有大数值和宽压力范围的NAC行为。我们发现，除了普遍认为的层的刚性扁平化之外，二硒化钯中意外的巨大NAC效应主要源于层内化学键的异常伸长。这两种结构变化都是由层内到层间的电荷转移驱动的，压力作用下增强的层间相互作用促进了这种电荷转移。我们的工作更新了对这种异常现象的力学理解，并为探索新型压缩诱导特性建立了新的指导原则。
