Boroxol Rings in Liquid and Vitreous<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi mathvariant="normal">B</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>from First Principles

Ferlat, G.; Charpentier, Thibault; Seitsonen, Ari P.; Takada, Akira; Lazzeri, Michele; Cormier, Laurent; Calas, Georges; Mauri, Francesco

doi:10.1103/physrevlett.101.065504

Cited by 142 publications

(120 citation statements)

References 48 publications

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…Interestingly, B 2 O 3 -I-b, the boroxol-made equivalent of B 2 O 3 -I, is found among the lowest energy polytypes. These findings, thus, confirm that boroxol rings are essential to stabilize low density structures [19] and explain the glass anomaly 3). We note that in the T10 structure, the dihedral angle distribution between adjacent ring and non-ring units is well in line with the one measured in the glass by twodimensional NMR [26]: this supports the idea that the glass shares structural similarities with the predicted polymorphs in the region of energy-density degeneracy.…”

supporting

confidence: 74%

“…1) [6,18,19]. Strangely, these rings, which can be viewed as superstructural units, are totally absent in both B 2 O 3 crystalline polymorphs.…”

mentioning

confidence: 97%

“…In addition, several studies have pointed out a structural link between the glassy and the known crystalline phases [4,5]. These connections may also have ramifications for the understanding of phenomena such as polyamorphism (existence of distinct amorphous states), liquid-liquid transitions and even possibly for protein folding [16].Boron oxide (B 2 O 3 ) is one of the simplest glass-forming oxides and has received considerable attention [6,[17][18][19][20][21]. It is one of the best glass formers, even a better one than silica, since it has never been observed to crystallize from a dry melt at ambient pressure: even if the melt is seeded with crystals and maintained for several months at various temperatures below the melting point, no crystal growth is observed at any imposed cooling rates (|dT /dt| > 10 −5 K.s −1 ) [7][8][9].…”

mentioning

confidence: 99%

“…Boron oxide (B 2 O 3 ) is one of the simplest glass-forming oxides and has received considerable attention [6,[17][18][19][20][21]. It is one of the best glass formers, even a better one than silica, since it has never been observed to crystallize from a dry melt at ambient pressure: even if the melt is seeded with crystals and maintained for several months at various temperatures below the melting point, no crystal growth is observed at any imposed cooling rates (|dT /dt| > 10 −5 K.s −1 ) [7][8][9].…”

mentioning

confidence: 99%

See 3 more Smart Citations

Hidden polymorphs drive vitrification in B2O3

Ferlat

Seitsonen²,

Lazzeri³

et al. 2012

Nature Mater

Self Cite

View full text Add to dashboard Cite

Understanding the conditions which favor crystallisation or vitrification of liquids has been a long-standing scientific problem [1][2][3]. Another connected, and not yet well understood question is the relationship between the glassy and the various possible crystalline forms a system may adopt [4,5]. In this context, B2O3 is a puzzling case of study since i) it is one of the best glass-forming systems despite an apparent lack of lowpressure polymorphism ii) it vitrifies in a glassy form abnormally different from the only known crystalline phase at ambient pressure [6] iii) it never crystallises from the melt unless pressure is applied, an intriguing behaviour known as the crystallisation anomaly [7][8][9]. Here, by means of ab-initio calculations, we discover the existence of novel B2O3 crystalline polymorphs with structural properties similar to the glass and formation energies comparable to the known ambient crystal. The resulting configurational degeneracy drives the system vitrification at ambient pressure. The degeneracy is lifted under pressure, unveiling the origin of the crystallisation anomaly. This work reconciles the behaviour of B2O3 with that from other glassy systems and reaffirms the role played by polymorphism in a system's ability to vitrify [10,11]. Some of the predicted crystals are cage-like materials entirely made of three-fold rings, opening new perspectives for the synthesis of boron-based nanoporous materials. PACS numbers:Polymorphism, the possibility for a substance to form several distinct crystalline phases of identical composition, is observed for a wide range of materials. This phenomenon has tremendous importance not only per se for understanding the crystallisation process but also because of practical implications such as the design and control of new materials with specific properties [12], a major issue for the pharmaceutical industry [13]. Indeed, the ability of molecular units to pack in various ways generates crystal phases which generally differ in their physical properties and cohesive energies. Another important implication of polymorphism is related to the glassy state: as pointed out earlier [10,11], glass formation is often prevalent for those materials which are found in a variety of crystalline forms. An obvious example is silica (SiO 2 ), the archetypal glass-former, which at low pressure is found as quartz, cristobalite, keatite, tridymite, coesite and moganite [14]. The existence of these many polytypes illustrate that the structural units, here the SiO 4 tetrahedra, can occur in several conformations with little difference in strain energy, allowing for the possibility of metastable states [14]. The ease of glass formation is usually understood as the result of the system frustration associated to the presence of many minima of comparable energy in the crystal energy landscape (CEL). In the context of organic chemistry, it has also been observed that systems with many almost equi-energetic structures containing a common interchangeable motif, correlate with a t...

show abstract

supporting

confidence: 74%

“…1) [6,18,19]. Strangely, these rings, which can be viewed as superstructural units, are totally absent in both B 2 O 3 crystalline polymorphs.…”

mentioning

confidence: 97%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Hidden polymorphs drive vitrification in B2O3

Ferlat

Seitsonen²,

Lazzeri³

et al. 2012

Nature Mater

Self Cite

View full text Add to dashboard Cite

show abstract

“…The microscopic structure of vitreous B 2 O 3 itself is still controversial and has attracted a lot of attention during the past years. [4][5][6] There is therefore a need to clarify the structure of such glasses and the relation between the structure and physical properties.…”

mentioning

confidence: 99%

Structural, dielectric, and optical properties of yttrium calcium borate glasses

Santos

Meneses²,

Echegut³

et al. 2009

Applied Physics Letters

View full text Add to dashboard Cite

Surface rippling on bulk metallic glass under nanosecond pulse laser ablation Appl. Phys. Lett. 99, 191902 (2011) Construction of a disorder variable from Steinhardt order parameters in binary mixtures at high densities in three dimensions J. Chem. Phys. 135, 174109 (2011) Fragility of iron-based glasses Appl. Phys. Lett. 99, 161902 (2011) Communication: Are metallic glasses different from other glasses? A closer look at their high frequency dynamics J. Chem. Phys. 135, 101101 (2011) Temperature dependence of the thermoplastic formability in bulk metallic glasses

show abstract

Towards Simulation‐Based Predictive Design of Glasses

Huang

Kieffer

2010

Ceramic Transactions Series

View full text Add to dashboard Cite

Boroxol Rings in Liquid and VitreousB2O3from First Principles

Cited by 142 publications

References 48 publications

Hidden polymorphs drive vitrification in B2O3

Hidden polymorphs drive vitrification in B2O3

Structural, dielectric, and optical properties of yttrium calcium borate glasses

Towards Simulation‐Based Predictive Design of Glasses

Contact Info

Product

Resources

About