Year: 2025
Type: preprint
Abstract: A potential orthorhombic phase of Ta$_2$O$_5$, designated as Y-Ta$_2$O$_5$, is predicted under high-pressure conditions through density functional theory (DFT) calculations combined with structural search algorithms. This phase, consisting of four formula units per unit cell ($Z = 4$), exhibits the highest known Ta-O coordination numbers. Y-Ta$_2$O$_5$ is found to be the most energetically favorable form of Ta$_2$O$_5$ in the pressure range of approximately 70 GPa to at least 200 GPa. Both standard DFT-GGA and higher-accuracy GW calculations reveal that Y-Ta$_2$O$_5$ is a wide bandgap semiconductor with a direct bandgap. Additionally, nuclear quantum effects (NQEs) introduce nontrivial corrections to external pressure at fixed volumes, underscoring their significance in high-pressure phase stability analyses.
Source: arXiv (Cornell University)
Authors: Gong, Yan, Tang, HuiMin, Yang, Yong, Kawazoe, Yoshiyuki
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4417428750
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