Dynamic glass transition and fragility of lithium borate binary glass

Matsuda, Yu; Fukawa, Yasuteru; Kawashima, Mitsuru; Mamiya, Seiichi; Kojima, Seiji

doi:10.1016/j.ssi.2008.09.011

Cited by 25 publications

(27 citation statements)

References 26 publications

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“…However, the formation of four‐coordinated boron in lithium borate glasses could enhance the connectivity inside the three‐dimensional network . There is strong correlation between the glass fragility and the fluctuation of the coordination number of boron . The glass density and four‐coordinated boron fraction are also strongly correlated …”

Section: Introductionmentioning

confidence: 99%

Thermochemical investigation of lithium borate glasses and crystals

Корытцева

Groß

et al. 2019

J Am Ceram Soc

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Lithium borate (LB) glasses and crystals with x = Li/(Li + B) = mole fraction of Li 2 O of 0.2-0.5 have been synthesized by the quenching method. The thermodynamics of these materials were analyzed by high-temperature oxide melt solution calorimetry. The formation enthalpies from oxides of glasses range from −33.6 to −67.3 kJ/mol and those of crystals range from −42.1 to −77.4 kJ/mol, where compositions are given on the basis of one mole of (Li 2 O + B 2 O 3 ). The formation enthalpies of both glasses and crystals become more negative with increasing Li 2 O mole fraction up to 0.5. The enthalpies of formation of glasses can be fit over the entire composition range (0 < x < 1) by a quadratic polynomial). The vitrification enthalpies were derived for x = 0.2 to 0.5 and ranged from 8.5 to 17.6 kJ/mol. The main factors controlling energetics are the strongly exothermic acid-base reaction between the network former (B 2 O 3 ) and the network modifier (Li 2 O) and the formation of tetrahedrally coordinated boron in the glasses and crystals.

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Section: Introductionmentioning

confidence: 99%

Thermochemical investigation of lithium borate glasses and crystals

Корытцева

Groß

et al. 2019

J Am Ceram Soc

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“…We have shown that the physical properties such as sound velocity, 9) stretched exponentiality KWW 10) and fragility 11) show the strong composition dependences.…”

mentioning

confidence: 96%

Composition Dependence of the Boson Peak and Universality in Lithium Borate Binary Glasses: Inelastic Neutron and Raman Scattering Studies

et al. 2010

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We study the low-energy vibrational dynamics, called the boson peak (BP), of binary lithium borate glasses as a function of the composition of these glasses by inelastic neutron and Raman scattering. Firstly, we analyze the variations in the properties of the BP with the composition. The position and intensity of the BP linearly change with increasing x owing to the changes in the intermediate glass structures. Secondly, we demonstrate that all spectral shapes with different compositions can be scaled by a single master curve, and are the same for all spectra. The results suggests that there is a universal distribution of the vibrational density of states, which does not change with the composition, even though the structures of lithium borate glasses markedly change. The effect of Li 2 O doping can be understood to be a chemical structure-induced densification.KEYWORDS: boson peak, low energy excitation, lithium borate glasses, vibrational density of states, inelastic neutron scattering, dynamic structure factor, Raman scattering DOI: 10.1143/JPSJ.79.033801A structurally disordered material shows physical properties different from those of its ordered crystalline counterpart. One of the most significant differences is the low frequency part of the vibrational spectra. A broad excitation peak, called a boson peak (BP), can be observed in the Raman and inelastic neutron spectra obtained at energies of approximately 2 -10 meV corresponding to the THz frequency range. The observation of the BP indicates the existence of an excess low-energy vibrational density of states (VDoS) beyond the prediction of the Debye model for crystals. Since the BP is commonly observed in many different types of disordered materials, it is considered that it must be the key to gaining a fundamental understanding of disordered materials. Despite constructive effort, the microscopic origin of the BP still remains a serious open question in condensed matter physics. 1-3)Boron oxide (B 2 O 3 ) glass is a typical network glass former, and classified into one of the ''strongest'' type of glass like SiO 2 glass, on the basis of its ''strong-fragile'' classification.4) The BP of pure B 2 O 3 glass was studied by inelastic neutron scattering (INS) 5) suggesting that its origin is related to the in-and random-phase motions of boroxol rings, and by hyper-Raman scattering 6) suggesting that the coherent librations of several boroxol rings are related to the hyper-Raman BP. Both results indicate that the BP of B 2 O 3 glass originates from the some type of vibrational motion of boroxol rings, which are considered an intermediate structural unit. The addition of lithium oxide (Li 2 O) to B 2 O 3 glass induces a change in the coordination number of boron atoms from 3 to 4, resulting in an increase in network connectivity with increasing Li 2 O content. 7,8) Therefore, the physical properties of binary lithium borate glasses,, where x is the Li 2 O content in mol %, markedly vary with x. We have shown that the physical properties such as sound velocity...

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“…TM‐DSC has previously been used to determine the fragility of both chalcogenide and oxide glass‐forming systems . However, due to instrumental limitations, this has been limited to glasses with low T g (below ~550°C), and it has thus not been suitable for many high‐ T g silicate glasses of industrial importance.…”

Section: Theorymentioning

confidence: 99%

“…Instead, a technique for measuring the structural relaxation time of glasses based on specific heat capacity spectroscopy measurements was proposed in 1985, using the thermal relaxation caused by the isothermal temperature oscillations to measure the structural relaxation time. Using the frequency dependence of the peak temperature (

T_{g}^{ω}

) in the imaginary heat capacity, TM‐DSC has successfully been applied to determine m of several borate‐based glass‐forming liquids ( T g ≈ 450°C) by converting frequency into relaxation time and using the following equation,

m false(x false) = {(|, \frac{d {log}_{10} τ false(T, x false)}{d (T_{g} false(x false) / T)})}_{T = T_{g} false(x false)} .

…”

Section: Theorymentioning

confidence: 99%

Liquid fragility determination of oxide glass‐formers using temperature‐modulated DSC

Bechgaard

Gulbiten

Mauro

et al. 2019

Int J of Appl Glass Sci

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Glass-forming liquids exhibit a pronounced diversity in the viscosity-temperature relation. This has been characterized by the liquid fragility index to quantify the extent of the non-Arrhenian flow. Precise and accurate determination of liquid fragility is important for understanding a range of phenomena and controlling industrial glass melting processes. In this study, we use temperature-modulated differential scanning calorimetry (TM-DSC) to determine liquid fragility of a wide range of oxide compositions, including tellurites, borates, and silicates. We compare our fragility data to those determined using viscometry and the Moynihan DSC approach. We find that TM-DSC is a useful method for determination of fragility, as it exhibits higher sensitivity and provides an easier and more reliable determination of characteristic temperatures compared to the Moynihan approach. Moreover, TM-DSC is faster and requires smaller sample volume compared to the viscometric approach. However, we also observe that TM-DSC tends to either overestimate or underestimate the fragility of very strong and highly fragile compositions, respectively. K E Y W O R D S liquid fragility, oxide glasses, temperature-modulated DSC How to cite this article: Bechgaard TK, Gulbiten O, Mauro JC, Yue Y, Bauchy M, Smedskjaer MM. Liquid fragility determination of oxide glass-formers using temperature-modulated DSC. Int J Appl Glass Sci.

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Dynamic glass transition and fragility of lithium borate binary glass

Cited by 25 publications

References 26 publications

Thermochemical investigation of lithium borate glasses and crystals

Thermochemical investigation of lithium borate glasses and crystals

Composition Dependence of the Boson Peak and Universality in Lithium Borate Binary Glasses: Inelastic Neutron and Raman Scattering Studies

Liquid fragility determination of oxide glass‐formers using temperature‐modulated DSC

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