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Sylwester J. Rzoska

Bio: Sylwester J. Rzoska is an academic researcher from Polish Academy of Sciences. The author has contributed to research in topics: Dielectric & Liquid crystal. The author has an hindex of 33, co-authored 216 publications receiving 3570 citations. Previous affiliations of Sylwester J. Rzoska include University of Silesia in Katowice & Silesian University.


Papers
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TL;DR: In this article, a melt-quenched lithium aluminoborate glass featuring the highest crack resistance for a bulk oxide glass is reported, which is based on combined mechanical and structural characterizations.
Abstract: Despite their transformative role in our society, oxide glasses remain brittle. Although extrinsic postprocessing techniques can partially mitigate this drawback, they come with undesirable side effects. Alternatively, topological engineering offers an attractive option to enhance the intrinsic strength and damage resistance of glass. On the basis of this approach, we report here the discovery of a novel melt-quenched lithium aluminoborate glass featuring the highest crack resistance ever reported for a bulk oxide glass. Relying on combined mechanical and structural characterizations, we demonstrate that this unusual damage resistance originates from a significant self-adaptivity of the local atomic topology under stress, which, based on a selection of various oxide glasses, is shown to control crack resistance. This renders the lithium aluminoborate glass a promising candidate for engineering applications, such as ultrathin, yet ultrastrong, protective screens.

107 citations

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TL;DR: In this paper, the authors examined changes in density, network structure, indentation hardness, and crack resistance of sodium aluminosilicate glasses with varying Al/Si ratio and thus non-bridging oxygen (NBO) content before and after 1 GPa isostatic compression at elevated temperature.
Abstract: Clarifying the effect of pressure on the structure of aluminosilicate glasses is important for understanding the densification mechanism of these materials under pressure and the corresponding changes in macroscopic properties. In this study, we examine changes in density, network structure, indentation hardness, and crack resistance of sodium aluminosilicate glasses with varying Al/Si ratio and thus non-bridging oxygen (NBO) content before and after 1 GPa isostatic compression at elevated temperature. With increasing NBO content, the silicate network depolymerizes, resulting in higher atomic packing density, lower hardness, and higher crack resistance. The ability of the glasses to densify under isostatic compression is higher in the high-NBO glasses, and these glasses also exhibit more pronounced pressure-induced changes in mechanical properties. The 27Al NMR data show a surprising presence of five-fold aluminum in the as-made high-NBO glasses, with additional formation upon compression. Our study therefore provides new insights into the complicated relationship between Al coordination and NBO content in aluminosilicate glasses and how it affects their densification behavior.

96 citations

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TL;DR: It is shown that thermal energy exerts a stronger influence than volume on the temperature dependence of the dynamic properties, and can be interpreted as a reflection of the soft nature of the potential.
Abstract: Dielectric relaxation and PVT measurements were carried out on propylene carbonate. From these, we show that thermal energy exerts a stronger influence than volume on the temperature dependence of the dynamic properties. Data obtained at all temperatures and pressures superimpose, when expressed as a function of T ˛1 V ˛3.7 . The scaling exponent is consistent with more thermally governed dynamics, and can be interpreted as a reflection of the soft nature of the potential. The change of dynamics observed in the conductivity and relaxation data transpires at a fixed value of either quantity, independent of temperature and pressure.

76 citations

Journal ArticleDOI
TL;DR: In this article, the authors reveal the origin of the high crack resistance by investigating changes in structure and mechanical properties in compositions ranging from peralkaline to peraluminous and by varying the pressure history through an isostatic N 2 -mediated pressure treatment at elevated temperature.
Abstract: Sodium aluminoborate glasses are found to exhibit favorable mechanical properties, especially high crack resistance, due to their relatively low resistance to network compaction during sharp-contact loading. We here reveal the origin of the high crack resistance by investigating changes in structure and mechanical properties in compositions ranging from peralkaline to peraluminous and by varying the pressure history through an isostatic N 2 -mediated pressure treatment at elevated temperature. This approach allows us to study the composition dependence of the ease of the glassy network compaction and the accompanying changes in structure and properties, which shed light on the processes occurring during indentation. Through solid state NMR measurements, we show that the network densification involves an increase in the average coordination number of both boron and aluminum and a shortening of the sodium-oxygen bond length. These changes in the short-range order of the glassy networks manifest themselves as an increase in, e.g., density and indentation hardness. We also demonstrate that the glasses most prone to network compaction exhibit the highest damage resistance, but surprisingly the crack resistance scales better with the relative density increase achieved by the hot compression treatment rather than with the extent of densification induced by indentation. This suggests that tuning the network structure may lead to the development of more damage resistant glasses, thus addressing the main drawback of this class of materials.

69 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the critical behavior of spin systems at equilibrium is studied in three and two dimensions, and the results in three-dimensional space are presented in particular for the six-loop perturbative series for the β -functions.

1,363 citations

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TL;DR: This work identifies the class of secondary relaxations that bears a strong connection or correlation to the primary relaxation in all the dynamic properties and proposes that only these should be called the Johari-Goldstein beta-relaxation.
Abstract: Dynamic properties, derived from dielectric relaxation spectra of glass-formers at variable temperature and pressure, are used to characterize and classify any resolved or unresolved secondary relaxation based on their different behaviors. The dynamic properties of the secondary relaxation used include: (1) the pressure and temperature dependences; (2) the separation between its relaxation time τβ and the primary relaxation time τα at any chosen τα; (3) whether τβ is approximately equal to the independent (primitive) relaxation time τ0 of the coupling model; (4) whether both τβ and τ0 have the same pressure and temperature dependences; (5) whether it is responsible for the “excess wing” of the primary relaxation observed in some glass-formers; (6) how the excess wing changes on aging, blending with another miscible glass-former, or increasing the molecular weight of the glass-former; (7) the change of temperature dependence of its dielectric strength Δeβ and τβ across the glass transition temperature Tg; ...

715 citations

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TL;DR: In this paper, a review of the mechanisms underlying the relaxation properties of glass-forming liquids and polymers is provided, with an emphasis in the insight provided into the mechanism underlying the glass relaxation properties.
Abstract: An intriguing problem in condensed matter physics is understanding the glass transition, in particular the dynamics in the equilibrium liquid close to vitrification Recent advances have been made by using hydrostatic pressure as an experimental variable These results are reviewed, with an emphasis in the insight provided into the mechanisms underlying the relaxation properties of glass-forming liquids and polymers

638 citations

Journal ArticleDOI
TL;DR: Although differential scanning calorimetry is the most widely used thermal analytical technique applied to the characterization of amorphous solid dispersions, there are many established and emerging techniques which have been shown to provide useful information.

399 citations