Negative Linear Compressibility and Interlayer Gap Closure in Layered Rare-Earth Hydroxyhalide (YCl(OH)2) under High
Mengzeng Wu1,2, Jingui Xu1, Dongzhou Zhang3
1Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, Guizhou, China.
Inorganic Chemistry
|January 24, 2024
Summary
This study reveals that Yttrium chloride hydroxide (YCl(OH)2) exhibits unique structural changes under high pressure, including negative linear compressibility along the b-axis due to hydrogen bonding. This provides insights into layered material behavior under extreme conditions.
Area of Science:
- Materials Science
- Crystallography
- High-Pressure Physics
Background:
- Layered materials possess unique properties making them vital for new functional materials.
- Understanding structural evolution under high pressure is critical for materials development.
Purpose of the Study:
- To investigate the structural evolution of YCl(OH)2 under high pressure.
- To determine the equation of state (EoS) parameters for YCl(OH)2.
- To elucidate the mechanism behind the observed anomalous compressibility.
Main Methods:
- Synchrotron single-crystal X-ray diffraction using a diamond anvil cell up to 9.4 GPa.
- High-pressure Raman spectroscopy up to 10.3 GPa.
- Fitting pressure-volume data to the third-order Birch-Murnaghan equation of state.
Main Results:
- YCl(OH)2 maintains its symmetry within the experimental pressure range.
- Derived EoS parameters: V0 = 142.47 ų, K0 = 38.2 GPa, K0' = 9.8.
- Observed distinct compressional behaviors along a, b, and c axes, with negative linear compressibility along the b-axis (0.4-5.3 GPa).
Conclusions:
- Anomalous b-axis compression is attributed to O-H···O hydrogen bonding chains.
- Y3+ coordination number increases from 8 to 9 due to interlayer spacing reduction.
- Compression leads to interlayer gap closure, influencing the material's structural response.
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