Order in the disordered state: local structural entities in the fast ion conductor Ba2In2O5

Mohn, Chris E.; Allan, Neil L.; Freeman, Colin L.; Ravindran, P.; Stølen, Svein

doi:10.1016/j.jssc.2004.10.044

Cited by 41 publications

(62 citation statements)

References 35 publications

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“…36 Using R i from Tables I and II, we find that V IT = 2.8 (GGA), whereas V HT = 2.3 (GGA). The largest contribution to the significantly higher value of V of the IT phase is the short Bi1-O2 bond of 2.21Å.…”

Section: Resultsmentioning

confidence: 92%

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
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27
0
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Ab initio electronic structure calculations are reported for the simplest (layered) Aurivillius compound, Bi 2 WO 6 , elucidating the role of the asymmetric Bi 6s lone-pair structure on the stability of the ferroelectric phase and the band structure. In contrast with the conventional view, where the nature of the para-to ferroelectric transition is explained by the formation of a short Bi-O bond to the perovskite layer, we show that the phase transition is accompanied by cooperative distortions of the asymmetric oxygen arrangements around the bismuth with the formation of particular short Bi-O bonds within the Bi 2 O 2 fluorite sheets. These changes are intimately connected to electronic properties, since while the high-temperature paraelectric phase possesses an indirect band gap, an unusual direct band gap is found at the zone center of the Brillouin zone for ferroelectric Bi 2 WO 6 .

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Section: Resultsmentioning

confidence: 92%

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
Self Cite
58
3
27
0
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show abstract

“…For this reason many doping strategies have been proposed in literature in order to stabilize the tetragonal and cubic structures of barium indate, among which one of the most interesting is the oxyanionic doping with PO 4 3and SO 4 2ions 21 . Moreover, computational studies reported a distribution of the oxygen vacancies for this system far from being random even at highest temperatures suggesting some discrepancy between the short range order and the average crystallographic structure 22 . In this context, an X-ray total scattering investigation at room temperature of the orthorhombic pure barium indate and the doped samples Ba 2 In 1.…”

Section: Oxide Ion Conductorsmentioning

confidence: 89%

Recent advances in the application of total scattering methods to functional materials

Mancini

Malavasi

2015

Chem. Commun.

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“…Such effects have been proposed earlier by Mohn et al in the context of ionic conductivity in Ba 2 In 2 O 5 . 31 To conclude, we have found novel low-energy ordered structures for the mixed Gd 2 Ti 2 O 7 -Gd 2 Zr 2 O 7 pyrochlores. The lowest energy structures are stabilized by an oxygen relaxation that allows for 7-fold coordination of some of the Zr cations in these structures.…”

Section: Discussionmentioning

confidence: 59%

Distortion-stabilized ordered structures in A2BB’O7 mixed pyrochlores

2019

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Pyrochlore oxides (A 2 B 2 O 7 ) are interesting for a number of technological applications, including radiation damage tolerance and as ionic conductors. Mixed pyrochlores-containing two A and/or two B site cations-provide even more flexibility for tailoring properties owing to the diverse chemical and configurational degrees of freedom accessible within this chemical space. Here, we examine relative stability of different cation orderings in one model double pyrochlore Gd 2 (Zr x Ti 1−x ) 2 O 7 , as a function of Zr content x. Our results show that, in the presence of some very specific local cation arrangements, certain cation-ordered compositions in this system are highly stabilized as a result of large oxygen relaxation displacements, leading to the formation of an ordered 'double' pyrochlore structure. The origins of these anomalous oxygen relaxations are traced back to both the local cation symmetry and a strong chemical preference of Zr atoms towards adopting a 7-fold coordination environment, as opposed to a 6-fold coordination available in a regular pyrochlore structure. Subsequently, we examine the stability of this type of ordering in 131 other pyrochlore compositions. Implications of our findings are discussed in relation to the observed composition-dependent ionic conductivity in these systems and connections with previously reported experimental findings are made.npj Computational Materials (2019) 5:7 ; https://doi.

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Order in the disordered state: local structural entities in the fast ion conductor Ba2In2O5

Cited by 41 publications

References 35 publications

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
Self Cite
58
3
27
0
View full text Add to dashboard Cite

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
Self Cite
58
3
27
0
View full text Add to dashboard Cite

Recent advances in the application of total scattering methods to functional materials

Distortion-stabilized ordered structures in A2BB’O7 mixed pyrochlores

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Order in the disordered state: local structural entities in the fast ion conductor Ba2In2O5

Cited by 41 publications

References 35 publications

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6Mohn1, Stølen2 2011Phys. Rev. BSelf Cite583270View full textAdd to dashboardCite

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6Mohn1, Stølen2 2011Phys. Rev. BSelf Cite583270View full textAdd to dashboardCite

Recent advances in the application of total scattering methods to functional materials

Distortion-stabilized ordered structures in A2BB’O7 mixed pyrochlores

Contact Info

Product

Resources

About

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
Self Cite
58
3
27
0
View full text Add to dashboard Cite

Influence of the stereochemically active bismuth lone pair structure on ferroelectricity and photocalytic activity of Aurivillius phase Bi2WO6
Mohn
¹
,
Stølen
²

2011
Phys. Rev. B
Self Cite
58
3
27
0
View full text Add to dashboard Cite