Functionalities of Au2O, Au2O3, Au2O3-x, and nanosheets, including spontaneous polarization, using DFT and hybrid functional

Fuente: arXiv
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Main Author: Watanabe, Yukio
Format: Preprint
Published: 2026
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author Watanabe, Yukio
author_facet Watanabe, Yukio
contents We used density functional theories (DFT) to investigate the properties of Au2O and Au2O3-x (x = 00.08) to reveal their remarkable functionalities. Hybrid functional theories accurately estimate the band gap (Eg) of oxides, and the present hybrid functional calculations determined Eg values of 0.96 eV for Au2O and 2.86 eV for Au2O3, which is >300% of the commonly accepted Eg of Au2O3 (0.85 eV). Moreover, we discovered spontaneous polarization (PS) in Au2O3, which is unusually large and advantageous for catalysis. The PS was retained even in 2-nm-thick Au2O3 nanosheets, similar to hyperferroelectric, generating a potential of 0.6 eV despite screening caused by surface reconstruction, which is a novel screening mechanism. Below a thickness of 0.8 nm, the PS vanished, and inversion symmetry emerged at 0.4 nm, suggesting a new approach to finding a paraelectric phase. Au2O was supersoft under shear distortion.
format Preprint
id arxiv_https___arxiv_org_abs_2601_18165
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Functionalities of Au2O, Au2O3, Au2O3-x, and nanosheets, including spontaneous polarization, using DFT and hybrid functional
Watanabe, Yukio
Materials Science
We used density functional theories (DFT) to investigate the properties of Au2O and Au2O3-x (x = 00.08) to reveal their remarkable functionalities. Hybrid functional theories accurately estimate the band gap (Eg) of oxides, and the present hybrid functional calculations determined Eg values of 0.96 eV for Au2O and 2.86 eV for Au2O3, which is >300% of the commonly accepted Eg of Au2O3 (0.85 eV). Moreover, we discovered spontaneous polarization (PS) in Au2O3, which is unusually large and advantageous for catalysis. The PS was retained even in 2-nm-thick Au2O3 nanosheets, similar to hyperferroelectric, generating a potential of 0.6 eV despite screening caused by surface reconstruction, which is a novel screening mechanism. Below a thickness of 0.8 nm, the PS vanished, and inversion symmetry emerged at 0.4 nm, suggesting a new approach to finding a paraelectric phase. Au2O was supersoft under shear distortion.
title Functionalities of Au2O, Au2O3, Au2O3-x, and nanosheets, including spontaneous polarization, using DFT and hybrid functional
topic Materials Science
url https://arxiv.org/abs/2601.18165