Pub Date : 2022-07-28DOI: 10.13036/17533562.63.5.15
Benjamin Guiselin, G. Tarjus, L. Berthier
Glass is everywhere. We use and are surrounded by glass objects which make tangible the reality of glass as a distinct state of matter. Yet, glass as we know it is usually obtained by cooling a liquid sufficiently rapidly below its melting point to avoid crystallisation. The viscosity of this supercooled liquid increases by many orders of magnitude upon cooling, until the liquid becomes essentially arrested on experimental timescales below the ‘glass transition‘ temperature. From a structural viewpoint, the obtained glass still very much resembles the disordered liquid, but from a mechanical viewpoint, it is as rigid as an ordered crystal. Does glass qualify as a separate state of matter? We provide a pedagogical perspective on this question using basic statistical mechanical concepts. We recall the definitions of states of matter and of phase transitions between them. We review recent theoretical results suggesting why and how an ‘ideal glass’ can indeed be defined as a separate equilibrium state of matter. We discuss recent success of computer simulations trying to analyse this glass state. We close with some experimental perspectives.
{"title":"Is glass a state of matter?","authors":"Benjamin Guiselin, G. Tarjus, L. Berthier","doi":"10.13036/17533562.63.5.15","DOIUrl":"https://doi.org/10.13036/17533562.63.5.15","url":null,"abstract":"Glass is everywhere. We use and are surrounded by glass objects which make tangible the reality of glass as a distinct state of matter. Yet, glass as we know it is usually obtained by cooling a liquid sufficiently rapidly below its melting point to avoid crystallisation. The viscosity of this supercooled liquid increases by many orders of magnitude upon cooling, until the liquid becomes essentially arrested on experimental timescales below the ‘glass transition‘ temperature. From a structural viewpoint, the obtained glass still very much resembles the disordered liquid, but from a mechanical viewpoint, it is as rigid as an ordered crystal. Does glass qualify as a separate state of matter? We provide a pedagogical perspective on this question using basic statistical mechanical concepts. We recall the definitions of states of matter and of phase transitions between them. We review recent theoretical results suggesting why and how an ‘ideal glass’ can indeed be defined as a separate equilibrium state of matter. We discuss recent success of computer simulations trying to analyse this glass state. We close with some experimental perspectives.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85934298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.2.15
Kathleen A. Siuzdak Weber, J. Shelby
The density, refractive index, thermal expansion coefficient, glass transformation temperature and d.c. conductivity have been determined for a number of lithium aluminoborate glasses. The glasses studied lie on lines of constant Al2O3 to Li2O concentration with values of 0 (binary lithium borate glasses), 1/2 and 1/1. The thermal expansion coefficient passes through a minimum for all three series of glasses, while the glass transformation temperature for each series passes through a maximum. This behaviour is characteristic of the borate anomaly for all three series of glasses. Replacement of B2O3 by Al2O3 in these glasses has only a slight effect on the density and refractive index. The d.c. electrical conductivity of these glasses is controlled by the Li2O concentration, with little change due to replacement of B2O3 by Al2O3.
{"title":"Properties of lithium aluminoborate glasses","authors":"Kathleen A. Siuzdak Weber, J. Shelby","doi":"10.13036/17533562.63.2.15","DOIUrl":"https://doi.org/10.13036/17533562.63.2.15","url":null,"abstract":"The density, refractive index, thermal expansion coefficient, glass transformation temperature and d.c. conductivity have been determined for a number of lithium aluminoborate glasses. The glasses studied lie on lines of constant Al2O3 to Li2O concentration with values of 0 (binary lithium borate glasses), 1/2 and 1/1. The thermal expansion coefficient passes through a minimum for all three series of glasses, while the glass transformation temperature for each series passes through a maximum. This behaviour is characteristic of the borate anomaly for all three series of glasses. Replacement of B2O3 by Al2O3 in these glasses has only a slight effect on the density and refractive index. The d.c. electrical conductivity of these glasses is controlled by the Li2O concentration, with little change due to replacement of B2O3 by Al2O3.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"74 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79271694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.5.09
D. B. Rapp, J. Shelby
The diffusivity and solubility of water at 1200°C has been measured in a series of sodium aluminosilicate melts. Both the diffusivity and solubility of water in these melts decrease as Na2O is replaced by Al2O3. The partial molar solubilities of SiO2, Na2O and Al2O3 have been determined. The diffusivity of water in these melts exhibits an inverse relationship with the viscosity of the melt, which can be extended to include sodium silicate melts at the same temperature. The glass transformation temperature of these glasses decreases with increasing water concentration. The magnitude of this effect is shown to be similar to that for many other compositional systems.
{"title":"Water diffusion and solubility in sodium aluminosilicate melts","authors":"D. B. Rapp, J. Shelby","doi":"10.13036/17533562.63.5.09","DOIUrl":"https://doi.org/10.13036/17533562.63.5.09","url":null,"abstract":"The diffusivity and solubility of water at 1200°C has been measured in a series of sodium aluminosilicate melts. Both the diffusivity and solubility of water in these melts decrease as Na2O is replaced by Al2O3. The partial molar solubilities of SiO2, Na2O and Al2O3 have been determined. The diffusivity of water in these melts exhibits an inverse relationship with the viscosity of the melt, which can be extended to include sodium silicate melts at the same temperature. The glass transformation temperature of these glasses decreases with increasing water concentration. The magnitude of this effect is shown to be similar to that for many other compositional systems.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"24 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83067064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.2.78
G. Srinivas, J. Shiva Kumar, M. Shareefuddin, M. Chary, R. Sayanna
Glasses with the composition xK2O–(25−x) Li2O–12·5BaO–12·5MgO–48B2O3–2V2O5 (0≤x≤20) were prepared by the melt quenching method. The mixed alkali effect (MAE) has been investigated in the glass system through density, molar volume, optical absorption and EPR studies. VO2+ ions were used as the spin probes. From the optical absorption studies the values of the optical band gap (Eopt) for indirect transitions and the Urbarch energy (∆E) were evaluated. The values of Eopt, ∆E and density exhibited nonlinear behaviour with the variation of Li2O content, which may be attributed to the mixed alkali effect. The EPR spectra have structures which are characteristic of a hyperfine interaction arising from an unpaired electron with the 51V nucleus and it builds up in intensity as x increases. The spin-Hamiltonian parameters were evaluated from the EPR spectra. For x=0 mol%, the EPR spectrum was found to be more intense and well resolved. The variation of g‖ versus A‖ and N versus 1/x as a function of Li2O content was found to be nonlinear, which may be due to the mixed alkali effect. The results obtained were explained.
{"title":"Optical and electron paramagnetic resonance studies of VO2+ doped mixed alkali–alkaline earth oxide borate glass system","authors":"G. Srinivas, J. Shiva Kumar, M. Shareefuddin, M. Chary, R. Sayanna","doi":"10.13036/17533562.63.2.78","DOIUrl":"https://doi.org/10.13036/17533562.63.2.78","url":null,"abstract":"Glasses with the composition xK2O–(25−x) Li2O–12·5BaO–12·5MgO–48B2O3–2V2O5 (0≤x≤20) were prepared by the melt quenching method. The mixed alkali effect (MAE) has been investigated in the glass system through density, molar volume, optical absorption and EPR studies. VO2+ ions were used as the spin probes. From the optical absorption studies the values of the optical band gap (Eopt) for indirect transitions and the Urbarch energy (∆E) were evaluated. The values of Eopt, ∆E and density exhibited nonlinear behaviour with the variation of Li2O content, which may be attributed to the mixed alkali effect. The EPR spectra have structures which are characteristic of a hyperfine interaction arising from an unpaired electron with the 51V nucleus and it builds up in intensity as x increases. The spin-Hamiltonian parameters were evaluated from the EPR spectra. For x=0 mol%, the EPR spectrum was found to be more intense and well resolved. The variation of g‖ versus A‖ and N versus 1/x as a function of Li2O content was found to be nonlinear, which may be due to the mixed alkali effect. The results obtained were explained.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"178 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80022569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.1.02
A. Wright, N. Vedishcheva
Whereas the cybotactic theory and thermodynamic modelling have proved invaluable tools in understanding the structures and properties of alkali silicate glasses, questions have been raised as to their validity for alkaline earth and related glasses such as PbO–SiO2. The present paper discusses the specific cases of the CaO–SiO2 and PbO–SiO2 systems, and it is shown that the presence of Si[3] units (silicate tetrahedra with three bridging and one nonbridging oxygen atoms) can easily be explained in terms of the thermodynamic equilibria that underlie the model of associated solutions and the cybotactic theory. Similarly, the much more random distribution of silicate tetrahedral species in PbO–SiO2 glasses derives from the amphoteric nature of PbO. A related question concerns the relevance of atomistic structural modelling/simulation to the evaluation of structural theories of glasses, but to date all of the models of binary silicate glasses have been generated using periodic boundary conditions, which means that they are incapable of reproducing the long range disorder that characterises the vitreous state. Furthermore, it is demonstrated that, in their present form, the RMC and related computer codes, such as EPSR, are fundamentally flawed, in that they merely involve the fitting of an early crystallite model to experimental diffraction data, albeit one where the average internal structure of the crystallites is based on a large highly disordered unit cell, but the crystallites themselves have an entirely unphysical shape. It is also concluded that, to fully interpret the structure of binary and multicomponent glasses, it is essential to study the relevant phase diagram, together with the structures of the thermodynamically-stable and metastable crystalline phases that occur in that particular glass-forming system, and to understand that, since the supercooled liquid is only transiently metastable, the cybotactic/chemical grouping species present in the final glass may not necessarily be determined by equilibrium thermodynamics, but may be greatly influenced by the quench rate. The temperature range over which these crystalline phases/polymorphs are stable is also important, as is the temperature dependence of the glass transition temperature, Tg, and its relationship to the solidus temperature, Ts, at the same composition. Only in this way is it possible to derive the maximum information concerning the structure of a given glass and, much more importantly, to explain why this glass has its particular structure. It is therefore concluded that the key to developing a comprehensive theory of the formation and structure of the vitreous state lies not with ever more precise determinations of the short range order (i.e. diffraction studies), but rather in understanding the role of the thermodynamic equilibria that drive the characteristic long wavelength fluctuations in both number density and composition that distinguish the vitreous from the crystall
{"title":"The structure of CaO–SiO2 and PbO–SiO2 glasses","authors":"A. Wright, N. Vedishcheva","doi":"10.13036/17533562.63.1.02","DOIUrl":"https://doi.org/10.13036/17533562.63.1.02","url":null,"abstract":"Whereas the cybotactic theory and thermodynamic modelling have proved invaluable tools in understanding the structures and properties of alkali silicate glasses, questions have been raised as to their validity for alkaline earth and related glasses such as PbO–SiO2. The present paper discusses the specific cases of the CaO–SiO2 and PbO–SiO2 systems, and it is shown that the presence of Si[3] units (silicate tetrahedra with three bridging and one nonbridging oxygen atoms) can easily be explained in terms of the thermodynamic equilibria that underlie the model of associated solutions and the cybotactic theory. Similarly, the much more random distribution of silicate tetrahedral species in PbO–SiO2 glasses derives from the amphoteric nature of PbO. A related question concerns the relevance of atomistic structural modelling/simulation to the evaluation of structural theories of glasses, but to date all of the models of binary silicate glasses have been generated using periodic boundary conditions, which means that they are incapable of reproducing the long range disorder that characterises the vitreous state. Furthermore, it is demonstrated that, in their present form, the RMC and related computer codes, such as EPSR, are fundamentally flawed, in that they merely involve the fitting of an early crystallite model to experimental diffraction data, albeit one where the average internal structure of the crystallites is based on a large highly disordered unit cell, but the crystallites themselves have an entirely unphysical shape. It is also concluded that, to fully interpret the structure of binary and multicomponent glasses, it is essential to study the relevant phase diagram, together with the structures of the thermodynamically-stable and metastable crystalline phases that occur in that particular glass-forming system, and to understand that, since the supercooled liquid is only transiently metastable, the cybotactic/chemical grouping species present in the final glass may not necessarily be determined by equilibrium thermodynamics, but may be greatly influenced by the quench rate. The temperature range over which these crystalline phases/polymorphs are stable is also important, as is the temperature dependence of the glass transition temperature, Tg, and its relationship to the solidus temperature, Ts, at the same composition. Only in this way is it possible to derive the maximum information concerning the structure of a given glass and, much more importantly, to explain why this glass has its particular structure. It is therefore concluded that the key to developing a comprehensive theory of the formation and structure of the vitreous state lies not with ever more precise determinations of the short range order (i.e. diffraction studies), but rather in understanding the role of the thermodynamic equilibria that drive the characteristic long wavelength fluctuations in both number density and composition that distinguish the vitreous from the crystall","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82889001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.1.11
J. Shelby
The immiscibility region covers most of the region of glass formation in the lithium strontium silicate system. Although the density, refractive index, and thermal expansion coefficient are insensitive to the presence of phase separation, the glass transformation temperature can be used to determine the limit of immiscibility in this system. The dilatometric softening temperature was used to determine the boundary the limit of connectivity of the silica-rich phase. The electrical conductivity and activation energy for conduction were used to determine the limit of connectivity of the lithium-rich phase.
{"title":"Phase separation and the properties of lithium strontium silicate glasses","authors":"J. Shelby","doi":"10.13036/17533562.63.1.11","DOIUrl":"https://doi.org/10.13036/17533562.63.1.11","url":null,"abstract":"The immiscibility region covers most of the region of glass formation in the lithium strontium silicate system. Although the density, refractive index, and thermal expansion coefficient are insensitive to the presence of phase separation, the glass transformation temperature can be used to determine the limit of immiscibility in this system. The dilatometric softening temperature was used to determine the boundary the limit of connectivity of the silica-rich phase. The electrical conductivity and activation energy for conduction were used to determine the limit of connectivity of the lithium-rich phase.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"35 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90746797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.3.02
Rajesh Siripuram, P. Satya Gopal Rao, S. Sripada
A new, transparent antimony-tellurite glass and glass-ceramic systems doped with Nb2O5 have been prepared by using the conventional melt quenching method and heat treatment process, respectively. Various physical, optical and structural studies were reported through XRD, TEM, SEM, ultraviolet-visible, Raman, infrared and ESR investigations. XRD analysis of glass and glass-ceramic samples revealed their amorphous and crystalline natures, respectively. The Williamson-Hall approach was used to determine the average crystallite size of synthesised glass-ceramics and the values were found to be in the range of 23 to 85 nm. The SEM result reveals that glass-ceramics contain perspicuous and haphazardly distributed nanoclusters possessing sizes in the range of 45 to 120 nm. TEM analysis shows the size of particles in the glass-ceramics is in the range of 10 to 90 nm. The Eopt of the glass system has decreased from 2·873 to 2·606 eV, whereas in the glass-ceramic system it is observed to increase from 1·340 to 1·748 eV. Raman and infrared spectral analysis confirm the existence of various structural units such as TeO4, TeO3+1, TeO3, NbO6, NbO4, SbO3 in the glass and glass ceramic systems.The ESR spectral analysis reveals that the (Δg‖/Δg^) parameter seems to decrease from 4·444 to 2·453 in glass sytem, whereas in glass-ceramics it is observed to increase from 2·357 to 4·188. Glass transition temperature and onset crystalline temperatures are influenced by the Nb2O5 in both glass and glass-ceramic samples.
{"title":"Comparative studies of structural and optical properties of Nb2O5–Sb2O3–TeO2 glass and glass-ceramics","authors":"Rajesh Siripuram, P. Satya Gopal Rao, S. Sripada","doi":"10.13036/17533562.63.3.02","DOIUrl":"https://doi.org/10.13036/17533562.63.3.02","url":null,"abstract":"A new, transparent antimony-tellurite glass and glass-ceramic systems doped with Nb2O5 have been prepared by using the conventional melt quenching method and heat treatment process, respectively. Various physical, optical and structural studies were reported through XRD, TEM, SEM, ultraviolet-visible, Raman, infrared and ESR investigations. XRD analysis of glass and glass-ceramic samples revealed their amorphous and crystalline natures, respectively. The Williamson-Hall approach was used to determine the average crystallite size of synthesised glass-ceramics and the values were found to be in the range of 23 to 85 nm. The SEM result reveals that glass-ceramics contain perspicuous and haphazardly distributed nanoclusters possessing sizes in the range of 45 to 120 nm. TEM analysis shows the size of particles in the glass-ceramics is in the range of 10 to 90 nm. The Eopt of the glass system has decreased from 2·873 to 2·606 eV, whereas in the glass-ceramic system it is observed to increase from 1·340 to 1·748 eV. Raman and infrared spectral analysis confirm the existence of various structural units such as TeO4, TeO3+1, TeO3, NbO6, NbO4, SbO3 in the glass and glass ceramic systems.The ESR spectral analysis reveals that the (Δg‖/Δg^) parameter seems to decrease from 4·444 to 2·453 in glass sytem, whereas in glass-ceramics it is observed to increase from 2·357 to 4·188. Glass transition temperature and onset crystalline temperatures are influenced by the Nb2O5 in both glass and glass-ceramic samples.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"19 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85406972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.13036/17533562.63.4.07
M. Hiebert, Jamie L. Weaver, T. Lam, N. Little, Ethan Hyde, E. Vicenzi, R. Phaneuf
Atomic layer deposited (ALD) amorphous aluminium oxide and titanium oxide coatings have been investigated for use in reducing the rate of silicate glass alteration. Mass spectrometric analysis of leachate from elevated temperature aqueous immersion alteration experiments showed a marked decrease in the concentration of released Na and Si from the glass when the vitrified material was ALD coated as compared to uncoated glass. This decrease is consistent with the proposed protective effect of the ALD coating. Additionally, visual observations indicate formation of significant amounts of amorphous, secondary phase sediment for immersed, uncoated glass. This sediment was not present in the solution of the ALD coated and altered glass samples. However, the ALD coating did delaminate after protracted immersion, a likely limiting factor of the efficacy of ALD coatings. This limitation may be mitigated through a proposed refinement of the ALD coating procedure.
{"title":"ALD deposited amorphous alumina coatings can slow glass alteration","authors":"M. Hiebert, Jamie L. Weaver, T. Lam, N. Little, Ethan Hyde, E. Vicenzi, R. Phaneuf","doi":"10.13036/17533562.63.4.07","DOIUrl":"https://doi.org/10.13036/17533562.63.4.07","url":null,"abstract":"Atomic layer deposited (ALD) amorphous aluminium oxide and titanium oxide coatings have been investigated for use in reducing the rate of silicate glass alteration. Mass spectrometric analysis of leachate from elevated temperature aqueous immersion alteration experiments showed a marked decrease in the concentration of released Na and Si from the glass when the vitrified material was ALD coated as compared to uncoated glass. This decrease is consistent with the proposed protective effect of the ALD coating. Additionally, visual observations indicate formation of significant amounts of amorphous, secondary phase sediment for immersed, uncoated glass. This sediment was not present in the solution of the ALD coated and altered glass samples. However, the ALD coating did delaminate after protracted immersion, a likely limiting factor of the efficacy of ALD coatings. This limitation may be mitigated through a proposed refinement of the ALD coating procedure.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"30 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89170513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-12DOI: 10.13036/17533562.61.6.KURKJIAN
C. Kurkjian, P. Gupta
Intrinsic strength is the strength of a glass without extrinsic flaws. Knowledge of the composition dependence of the intrinsic strength is important both technologically for the development of high strength glass compositions and theoretically as it may provide important structural information. Intrinsic strength is easy to define but difficult to measure experimentally. In this paper we discuss intrinsic (σ*) strength measured in normal laboratory conditions as well as the inert intrinsic (σ0*) strength. We define these terms in a rigorous manner and indicate how to gauge if they have been measured by developing a set of criteria. Based on these criteria, we tabulate those values of intrinsic strengths that have been measured to date.
{"title":"Intrinsic strength and the structure of glass","authors":"C. Kurkjian, P. Gupta","doi":"10.13036/17533562.61.6.KURKJIAN","DOIUrl":"https://doi.org/10.13036/17533562.61.6.KURKJIAN","url":null,"abstract":"Intrinsic strength is the strength of a glass without extrinsic flaws. Knowledge of the composition dependence of the intrinsic strength is important both technologically for the development of high strength glass compositions and theoretically as it may provide important structural information. Intrinsic strength is easy to define but difficult to measure experimentally. In this paper we discuss intrinsic (σ*) strength measured in normal laboratory conditions as well as the inert intrinsic (σ0*) strength. We define these terms in a rigorous manner and indicate how to gauge if they have been measured by developing a set of criteria. Based on these criteria, we tabulate those values of intrinsic strengths that have been measured to date.","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"24 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82167234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-12DOI: 10.13036/17533562.61.6.006
I. Avramov, J. Šesták
The modelling of reaction kinetics is a fashionable subject of publications. We developed an analogue of the KJMA equation under non-isothermal conditions α(T)=1−exp(−(T/θ)N) that describes the dependence of degree of transformation α(T) at a constant rate, q, of heating with characteristic temperature θ(q) and power N, proportional to the Avrami parameter, n. This equation is valid even when the activation energy of the process is not constant. We demonstrate that reliable information about the activation energy is obtained when the experimental data are plotted in coordinates: logq (heating rate) against logTp (peak temperature).
{"title":"Generalised kinetics of overall phase transition useful for glass crystallisation when assuming non-isothermal conditions","authors":"I. Avramov, J. Šesták","doi":"10.13036/17533562.61.6.006","DOIUrl":"https://doi.org/10.13036/17533562.61.6.006","url":null,"abstract":"The modelling of reaction kinetics is a fashionable subject of publications. We developed an analogue of the KJMA equation under non-isothermal conditions α(T)=1−exp(−(T/θ)N) that describes the dependence of degree of transformation α(T) at a constant rate, q, of heating with characteristic temperature θ(q) and power N, proportional to the Avrami parameter, n. This equation is valid even when the activation energy of the process is not constant. We demonstrate that reliable information about the activation energy is obtained when the experimental data are plotted in coordinates: logq (heating rate) against logTp (peak temperature).","PeriodicalId":49696,"journal":{"name":"Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B","volume":"59 4 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2020-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88300258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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