Oxygen vacancy configuration of δ‐Bi2O3: an ab initio study

Zhong, Guo‐Hua; Wang, Yao; Dai, Zhaoxin; Wang, Jianglong; Zeng, Zhi

doi:10.1002/pssb.200844271

Cited by 18 publications

(5 citation statements)

References 24 publications

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“…To reduce the interaction between the neighboring vacancies, we now consider a supercell of δ-Bi 2 O 3 built by repeating the unit cell of Bi 2 O 3 2×2×2 times. It has been previously shown that the (110) vacancy alignment is the most favorable in δ-Bi 2 O 3 [33]. We have calculated the oxygen vacancy diffusion barriers in different vacancies configurations for one and two vacancies, as shown in figure 5.…”

Section: Resultsmentioning

confidence: 99%

Effect of high oxygen deficiency in nano-confined bismuth sesquioxide

et al. 2020

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Bismuth sesquioxide in its cubic form, i.e. δ-Bi 2 O 3 , is the fastest oxygen ionic conductor known which has important applications in energy technologies. However, the material is unstable as it undergoes high-density polymorphic transitions and degradation. In this work, we show that δ-Bi 2 O 3 can be stabilized both at high and low temperatures (T<775°C) under low oxygen partial pressure (pO 2 <10 −5 atm), where the material is nanostructured in multilayered thin film coherent heterostructures with yttrium stabilized zirconia. Density Functional Theory calculation confirms such a form of metastability, also showing that high oxygen defect concentration favors the cubic phase. Moreover, high oxygen deficiency in the nanoionics leads to an unexpected 'two-regime' conductivity with high values (σ>1 S cm −1 at 600°C) at high pO 2 and lower ionic conductivity (σ∼0.1 S cm −1 at 600°C) at low pO 2 . Ionic conductivity at low pO 2 occurs with high activation energy (Ea>1.5 eV), suggesting a drastic decrease in mobility for high concentration of defects.

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Section: Resultsmentioning

confidence: 99%

Effect of high oxygen deficiency in nano-confined bismuth sesquioxide

et al. 2020

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“…Typically, the thickness of surface oxide layers is much lower (of the order of nanometers for SiO 2 on Si [51–52]). In our case it is increased by the electric field and good oxygen mobility in BiO x due to the formation of charged Bi vacancies [59–60].…”

Section: Resultsmentioning

confidence: 99%

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

Knotek

Plechäček

Smolík

et al. 2019

Beilstein J. Nanotechnol.

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This study deals with the preparation and characterization of metallic nanoinclusions on the surface of semiconducting Bi2Se3 that could be used for an enhancement of the efficiency of thermoelectric materials. We used Au forming a 1D alloy through diffusion (point nanoinclusion) and Mo forming thermodynamically stable layered MoSe2 nanosheets through the reaction with the Bi2Se3. The Schottky barrier formed by the 1D and 2D nanoinclusions was characterized by means of atomic force microscopy (AFM). We used Kelvin probe force microscopy (KPFM) in ambient atmosphere at the nanoscale and compared the results to those of ultraviolet photoelectron spectroscopy (UPS) in UHV at the macroscale. The existence of the Schottky barrier was demonstrated at +120 meV for the Mo layer and −80 meV for the Au layer reflecting the formation of MoSe2 and Au/Bi2Se3 alloy, respectively. The results of both methods (KPFM and UPS) were in good agreement. We revealed that long-time exposure (tens of seconds) to the electrical field leads to deep oxidation and the formation of perturbations greater than 1 µm in height, which hinder the I–V measurements.

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“…Similar vacancy ordering has also been observed in neutrondiffraction experiments [7] conducted on rare-earth-doped δ-Bi 2 O 3 . Extensive research has been performed in identifying the lowest energy vacancy-ordered structure of δ-Bi 2 O 3 , and <100> [8][9][10], <110> [11] or <111> [12] vacancyordering models have also been proposed. We have shown from first-principles calculations that <110>-<111> model is the lowest energy model among either of <100>, <110>, or <111>.…”

Section: Introductionmentioning

confidence: 99%

Effect of ionic polarizability on oxygen diffusion in δ-Bi2O3 from atomistic simulation

Aidhy

Sinnott

Wachsman

et al. 2010

Ionics

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The effect of polarizability of cation dopants on oxygen diffusion in δ-Bi 2 O 3 is determined using moleculardynamics simulation in which the polarizability of the ions is treated within the shell model. It is found that the magnitude of the oxygen polarizability has no affect on diffusion. However, the high cation polarizability, associated with the lone pair of electrons in Bi, is found to be the key to achieving sustained oxygen diffusion. Consistent with earlier experimental results, the oxygen diffusion path is found to be between oxygen equilibrium sites, which are displaced from the 8c oxygen sites of the fluorite lattice.

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Oxygen vacancy configuration of δ‐Bi₂O₃: an ab initio study

Cited by 18 publications

References 24 publications

Effect of high oxygen deficiency in nano-confined bismuth sesquioxide

Effect of high oxygen deficiency in nano-confined bismuth sesquioxide

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

Effect of ionic polarizability on oxygen diffusion in δ-Bi2O3 from atomistic simulation

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