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Updated: Jun 10, 2026
11:21
Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes
Published on: March 21, 2018
Segregation into layers: a general problem for structural instability under pressure, exemplified by SnH4.
Paulina Gonzalez-Morelos1, Roald Hoffmann, N W Ashcroft
1Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, NY 14853-1301, USA.
Summary
Thermodynamically unstable compounds like stannane (SnH4) can form layered structures at moderate pressures. These structures balance novel electronic configurations against decomposition, disappearing at higher pressures.
Area of Science:
- Materials Science
- Computational Chemistry
- Solid-State Physics
Background:
- Thermodynamically unstable compounds can exhibit kinetic persistence.
- Layered structures may form as a compromise between stability and decomposition.
Purpose of the Study:
- To theoretically investigate the pressure-induced structural evolution of stannane (SnH4).
- To understand the role of segregated layers in unstable compounds under pressure.
Main Methods:
- Ground-state Density Functional Theory (DFT) searches.
- Modeling of layered structures with varying tin and hydrogen configurations.
- High-pressure simulations up to 140 GPa.
Main Results:
- Segregated tin and hydrogen layers are favored at lower to moderate pressures (0-50 GPa).
- At 140 GPa, tin-hydrogen coordination increases, and layered structures disappear.
- The study confirms layered structures as a key feature in the moderate-pressure regime.
Conclusions:
- Layered elemental segregation is a viable structural motif for kinetically persistent, thermodynamically unstable compounds.
- Pressure drives structural transitions, leading to increased coordination and loss of layered order.
- This approach provides insights into the behavior of unstable hydrides under extreme conditions.
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