X-Ray Crystallographic Study of Phase Transformation of Borax during Thermal Treatments

Dasgupta, D.; Banerjee, B. K.

doi:10.1063/1.1740695

Cited by 6 publications

(34 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results reveal the borate response to the load through a two-stage transformation: rearrangement at low pressure and polymerization at high pressure. The pressure required to initiate the polymerization depends directly on the portion of fourfold-coordinated ( [4] B) boron in the sodium borates. We found that the polymerization occurs through three different mechanisms to form BO 4 tetrahedra with surface oxygen and nonbridging and bridging oxygen.…”

mentioning

confidence: 99%

Mechanisms of Pressure-Induced Structural Transformation in Confined Sodium Borate Glasses

Zhu

et al. 2019

J. Phys. Chem. B

View full text Add to dashboard Cite

In this paper, density functional theory simulations were conducted to investigate the structural adaptation of sodium borates xNa2O·(100-x)B2O3 (x = 25, 33, 50, and 60 mol %) during the compression/decompression between 0 and 10 GPa. The sodium borates are confined between two Fe2O3 substrates and undergo the compression by reducing the gap between the two surfaces. The results reveal the borate response to the load through a two-stage transformation: rearrangement at low pressure and polymerization at high pressure. The pressure required to initiate the polymerization depends directly on the portion of fourfold-coordinated ([4]B) boron in the sodium borates. We found that the polymerization occurs through three different mechanisms to form BO4 tetrahedra with surface oxygen and nonbridging and bridging oxygen. The electronic structure was analyzed to understand the nature of these mechanisms. The conversions from BO3 to BO4 are mostly irreversible as a large number of newly formed BO4 remain unchanged under the decompression. In addition, the formation of a sodium-rich layer can be observed when the systems were compressed to high pressure. Our simulation provides insight into sodium borate glass responses to extreme condition and the underlying electronic mechanisms that can account for these behaviors.

show abstract

mentioning

confidence: 99%

Mechanisms of Pressure-Induced Structural Transformation in Confined Sodium Borate Glasses

Zhu

et al. 2019

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…In the range from room temperature to 480°C (where the sharp increase in the ionic mobility does not manifest itself), the thermal expansion along the crystallographic axes is nearly isotropic (Table 1, 2). However, at temperatures higher than 480°C, the significant changes in the unit cell angles lead to anisotropic thermal deformations of the α-Na 2 B 4 O 7 structure ( Table 2).…”

Section: Thermal Deformations Of the α-Na 2 B 4 O 7 And β-Nab 3 O 5 Bmentioning

confidence: 92%

“…This effect was also observed using differential thermal analysis: the effect at a temperature of 773°C in [7] was interpreted as congruent melting of the α triborate, although X-ray diffraction data were also absent. The effect at a temperature of 675°C was revealed in [2,3].…”

Section: Peritectic Melting Of the β-Nab 3 O 5 Boratementioning

confidence: 99%

“…The Na 2 -B 2 O 3 system has been investigated repeatedly [1][2][3][4][5][6][7]. However, the X-ray diffraction data reported for almost all phases in the system are rather contradictory.…”

Section: -B 2 O 3 Systemmentioning

confidence: 99%

“…In [1,3,7], the endothermal effects at temperatures of 720-728 and 740°C are interpreted as follows: the first effect is attributed to metastable melting of the α phase [3] or the β phase [7], the second effect is assigned to metastable melting of the β phase [3], and the last endothermal effect at a temperature of 765°C is associated with peritectic melting of the stable α phase [1][2][3] or congruent melting of the same α phase [7]. In this respect, we in situ investigated melting of the β-NaB 3 O 5 phase by high-temperature X-ray diffraction with the use of the techniques developed in [22,23].…”

Section: The Nab 3 O 5 Compoundmentioning

confidence: 99%

See 2 more Smart Citations

High-temperature crystal chemistry of α-Na2B4O7 and β-NaB3O5 layered borates

et al. 2007

View full text Add to dashboard Cite

The thermal expansion of two layered sodium borates is investigated using high-temperature X-ray powder diffraction. It is established that both compounds are characterized by strong anisotropy of thermal expansion due to the hinge mechanism. Special (singular) points are revealed in the temperature dependences of the angular lattice parameters for the α -Na 2 B 4 O 7 compound. The temperature of manifestation of these singularities corresponds to the glass transition temperature of the melt of the same chemical composition. The assumption is made that the angular lattice parameters (angles between atomic rows) in compounds with a considerable degree of ionic bonding are more sensitive to variations in temperature as compared to the linear lattice parameters (interatomic distances). It is experimentally in situ demonstrated with high-temperature X-ray diffraction that the β -NaB 3 O 5 borate is peritectically melted at a temperature of 725 ± 10 ° C with the formation of the α -Na 2 B 8 O 13 octaborate.

show abstract

d7033, XIII.2.1 Simple oxo-compounds of boron (oxoborates)

Allmann¹,

Pies²,

Weiss³

Key Elements: B, Al, Ga, In, Tl - Be

View full text Add to dashboard Cite

X-Ray Crystallographic Study of Phase Transformation of Borax during Thermal Treatments

Abstract: Xray diffraction studies of microstructural transformations in singlecrystal silicon during current filamentation

Cited by 6 publications

References 3 publications

Mechanisms of Pressure-Induced Structural Transformation in Confined Sodium Borate Glasses

Mechanisms of Pressure-Induced Structural Transformation in Confined Sodium Borate Glasses

High-temperature crystal chemistry of α-Na2B4O7 and β-NaB3O5 layered borates

d7033, XIII.2.1 Simple oxo-compounds of boron (oxoborates)

Contact Info

Product

Resources

About