Unexpected giant negative area compressibility in palladium diselenide

Xingxing Jiang; Shengzi Zhang; Dequan Jiang; Yonggang Wang; Maxim S Molokeev; Naizheng Wang; Youquan Liu; Xingyu Zhang; Zheshuai Lin

doi:10.1093/nsr/nwad016

Unexpected giant negative area compressibility in palladium diselenide

Natl Sci Rev. 2023 Jan 20;10(9):nwad016. doi: 10.1093/nsr/nwad016. eCollection 2023 Sep.

Authors

Xingxing Jiang^{1

2}, Shengzi Zhang^{1

3}, Dequan Jiang⁴, Yonggang Wang⁵, Maxim S Molokeev^{6

7

8}, Naizheng Wang^{1

3}, Youquan Liu^{1

3}, Xingyu Zhang^{1

3}, Zheshuai Lin^{1

2

3}

Affiliations

¹ 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.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Center for High Pressure Science & Technology Advanced Research, Beijing 100094, China.
⁵ School of Materials Science and Engineering, Peking University, Beijing 100871, China.
⁶ Laboratory of Crystal Physics, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036, Russia.
⁷ Department of Physics, Far Eastern State Transport University, Khabarovsk 680021, Russia.
⁸ International Research Center of Spectroscopy and Quantum Chemistry, Siberian Federal University, Krasnoyarsk 660041, Russia.

Abstract

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 PdSe₂ 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.

Keywords: Lifshitz mechanism; charge transfer; negative area compressibility.