First-principles study of structure, mechanical and optical properties of La- and Sc-doped Y2O3

Zhang, Xian; Gao, Sen; Gui, Wenhua; Zeng, Qingfeng

doi:10.1016/j.jre.2018.11.004

Cited by 18 publications

(7 citation statements)

References 48 publications

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“…On the base of this result, we can imagine a similar working mechanism respect to the case of CeO 2 -ZnO heterostructure, inter alia the migration of the photoexcited electrons from the ZnO CB to the 4f empty levels of cerium atoms. Analyzing in detail the chemical character of the Yb 3+ ions of Yb 2 O 3 compounds, the 4f level are not completely empty and oppositely to cerium, they are almost full [93][94][95]: this situation does not favor a remarkable electronic transition. In any case, it is present as for the CeO 2 -ZnO interface.…”

Section: Discussionmentioning

confidence: 96%

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Cerrato¹,

Gonçalves²,

Calza³

et al. 2020

Catalysts

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In this paper we compare the photocatalytic activity of two semiconductors based on ZnO: ZnO/CeO2 and ZnO/Yb2O3. The two samples were prepared via hydrothermal synthesis and fully characterized by X-ray diffraction technique, diffuse reflectance Ultra Violet- Visible spectroscopy (UV-Vis), high resolution transmission electron microscopy and finally with electron paramagnetic resonance spectroscopy. The prepared materials were also tested in their photocatalytic performances both through Electron Paramagnetic Resonance (EPR) analyzing the formation of charge carriers and with the abatement of a probe molecule like phenol, in presence and in absence of scavengers.

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Section: Discussionmentioning

confidence: 96%

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Cerrato¹,

Gonçalves²,

Calza³

et al. 2020

Catalysts

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“…The highest band gap value is in very good agreement with the room-temperature band gap values reported in the literature for single-crystal c-Y 2 O 3 . ,, The value of 5.80 eV is also in good agreement with the E g,opt values (5.68–5.88 eV) reported for monoclinic powders . Both values are, also, in good agreement with band gap values of yttria theoretically derived by using a DFT-based method. − As for h-Y 2 O 3 we are not aware of any experimental E g value reported in the literature for this polymorph, while E g values around 5.62 eV have been estimated by DFT-methods also for c-Y 2 O 3 . Although it is confirmed the usual scattering of experimental band gap values as a function of sample preparations and techniques of investigation, the literature data seem to confirm an appreciably higher band gap value for c-Y 2 O 3 with respect to the monoclinic polymorph as suggested in our semiempirical approach.…”

Section: Band Gap Estimation Of Y2o3 and Lu2o3 Polymorphs And Ternary...mentioning

confidence: 99%

Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y₃(Al_xGa_1–x)₅O₁₂ (YAGG) and Lu₃(Al_xGa_1–x)₅O₁₂ (LuAGG). A Semiempirical Approach

et al. 2022

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A further generalization to quaternary oxide systems of the modeling equation of optical band gap values, based on the semiempirical correlation between the differences in the electronegativity of oxygen and the average cationic electronegativity, proposed some years ago, has been carried out by expanding the approach recently employed for ternary mixed oxides. The choice of oxide polymorphs and their influence on the fitting procedure of an experimental data set is evidenced by a detailed discussion of the fitting process of the literature's experimental band gap data pertaining two quaternary oxide systems of the garnet family, namely, Y 3 (Al x Ga 1−x ) 5 O 12 (YAGG) and Lu 3 (Al x Ga 1−x ) 5 O 12 (LuAGG), playing an important role in several engineering applications. The two investigated systems, moreover, span a quite large range of band gap energy values (from ∼5.5 to ∼7.5 eV), as a function of the Al/Ga ratio, allowing a rigorous test of the proposed modeling equation. Based on the wide existing literature on the presence of excitonic effects in the investigated systems some empirical correlations between an optical gap and a band gap in the presence of excitonic effects are suggested, too, which could provide some rationale to overcome the discrepancies frequently encountered in comparing band gap values reported in the literature for the same materials. The results of this work confirm the ability of this semiempirical approach in providing good agreement between experimental and theoretical band gap values also for very complex systems, where more sophisticated density functional theory-based methods face some difficulties in predicting the correct values.

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“…The synergy of these advantages may occur in the (Y1-xScx)2O3 solid solution. In fact, several studies have shown that, for the solid solutions, not only ultrashort pulse laser and larger emission bandwidths than constituent sesquioxide can be achieved, but also the mechanical toughness and hardness can be enhanced [18,19]. Therefore, excellent optical and mechanical properties are highly anticipated in the (pristine and rare-earth-doped) Sc2O3-Y2O3 solid solution.…”

Section: Introductionmentioning

confidence: 99%

Optical, Thermal, and Mechanical Properties of (Y1-xScx)2O3 Transparent Ceramics

Huang

Yang

Huang

et al. 2021

Preprint

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Sesquioxides such as Y2O3 and Sc2O3 are important optical materials, but the fabrication of their transparent ceramics remains a challenge due to the ultra-high melting point of over 2400 oC. In this work, a series of (Y1-xScx)2O3 transparent ceramics were successfully fabricated by a simple vacuum sintering process without any sintering additives, and the effect of Scandium (Sc) content on the crystal structure and optical/thermal/mechanical properties were evaluated. Y2O3 and Sc2O3 form a complete solid solution with a cubic bixbyite structure. The formation of (Y1-xScx)2O3 solid solution promotes the densification of ceramics, leading to the realization of high transparency close to the theoretical transmittance over a wide wavelength range of 0.35-8 mm. In particular, the in-line transmittance in the range of 0.6-6 mm remains above 80% for (Y1-xScx)2O3 with x = 0.23-0.31, while the pristine Y2O3 and Sc2O3 are opaque. Moreover, the mechanical properties including Vickers hardness (Hv), fracture toughness (KIC), and biaxial strength (δb) are evidently enhanced due to the solid solution strengthening, while the thermal conductivity is reduced due to the reduction of photon free path. This study demonstrates that forming of solid solution is a facile and universal approach for preparing sesquioxides transparent ceramics with high optical and mechanical quality.

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First-principles study of structure, mechanical and optical properties of La- and Sc-doped Y2O3

Cited by 18 publications

References 48 publications

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y₃(Al_xGa_1–x)₅O₁₂ (YAGG) and Lu₃(Al_xGa_1–x)₅O₁₂ (LuAGG). A Semiempirical Approach

Optical, Thermal, and Mechanical Properties of (Y1-xScx)2O3 Transparent Ceramics

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First-principles study of structure, mechanical and optical properties of La- and Sc-doped Y2O3

Cited by 18 publications

References 48 publications

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Comparison of the Photocatalytic Activity of ZnO/CeO2 and ZnO/Yb2O3 Mixed Systems in the Phenol Removal from Water: A Mechanicistic Approach

Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y3(AlxGa1–x)5O12 (YAGG) and Lu3(AlxGa1–x)5O12 (LuAGG). A Semiempirical Approach

Optical, Thermal, and Mechanical Properties of (Y1-xScx)2O3 Transparent Ceramics

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Product

Resources

About

Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y₃(Al_xGa_1–x)₅O₁₂ (YAGG) and Lu₃(Al_xGa_1–x)₅O₁₂ (LuAGG). A Semiempirical Approach