Reduction‐Induced Inward Diffusion and Crystal Growth on the Surfaces of Iron‐Bearing Silicate Glasses

Liu, Shujiang; Tao, Haizheng; Zhang, Yanfei; Yue, Yuanzheng

doi:10.1111/jace.13587

Cited by 14 publications

(3 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, we focus on the effects of Mg. It is well established that the Mg coordination number (CN) (4, 5, or 6) changed discontinuously according to the field strengths of competing modifier cations in silicate glasses. Previous work indicated that the molar ratio of R + (alkali ions):Mg 2+ should have an important effect on the CN of Mg. Further systematic investigations indicated that the CN of Mg should be controlled by the average field strength of modifier cations.…”

Section: Discussionmentioning

confidence: 99%

Mixed alkaline‐earth effect on the mechanical and rheological properties of Ca–Mg silicate glasses

Shan

Tao

2017

J Am Ceram Soc

Self Cite

View full text Add to dashboard Cite

In this article, we investigate the mixed alkaline-earth effect in a silicate glass series with varying the molar ratio of [MgO]/([CaO]+ [MgO]). This effect manifests itself as a minimum in Vickers microhardness (H V ), coefficient of thermal expansion (CTE), and isokom temperatures at 10 12 (T g ) and 10 2 PaÁs, and as a maximum in liquid fragility. To probe the structural origin of the mixed alkaline-earth effect in CTE and H v , we conducted the Raman measurements. In contrast to the aluminosilicate glasses, the present glass series exhibit a negative deviation of shift of peak position at~1100 cm À1 from a linear additivity, indicating the role of the aluminum speciation in affecting the vibration modes. By fitting the Vogel-Fulcher-Tamann equation to the high-temperature viscosity data, we found a near-linear increase of the fractional free volume with the gradual substitution of Ca by Mg, confirming the dynamic structural mismatch model describing the mixed modifier effect. This work gives insight into the mixed modifier effect in glassy systems. K E Y W O R D Sglass, hardness, mixed modifier effect, structure, viscosity

show abstract

Section: Discussionmentioning

confidence: 99%

Mixed alkaline‐earth effect on the mechanical and rheological properties of Ca–Mg silicate glasses

Shan

Tao

2017

J Am Ceram Soc

Self Cite

View full text Add to dashboard Cite

show abstract

“…As is known, different types of alkaline‐earth ions have different abilities to attract the nonbridging oxygen (NBO) in glass, depending on the ion size. With substituting small alkaline‐earth ions for big ones in glass, the field strength ( F ) increases, that is,

F_{{Sr}^{2 +}} < F_{{Ca}^{2 +}} < F_{{Mg}^{2 +}}

, and hence, the ability of the alkaline‐earth ion to attract NBO increases in the same order 26 . As a consequence, the number of bridging oxygens per network forming cation (Si 4+ and Al 3+ ) rises and thus the structural network gets more connected.…”

Section: Resultsmentioning

confidence: 99%

Structure, crystallization, and performances of alkaline‐earth boroaluminosilicate sealing glasses for SOFCs

et al. 2021

Self Cite

View full text Add to dashboard Cite

We study the structure, crystallization, and performances of the sealing glasses with the composition (mol.%) of 12Al2O3·8B2O3·40SiO2·40RO (R = Mg, Ca, Sr) for solid oxide fuel cells (SOFCs) before and after isothermal treatment at 700°C, which is within the operation temperature range (600‐800°C) of SOFCs. The crystallization behavior has been investigated by differential scanning calorimetry and X‐ray diffraction under both dynamic and isothermal conditions. The structural evolution is probed using the Raman and nuclear magnetic resonance spectroscopies. The performances of the sealing glasses are characterized in terms of the coefficient of thermal expansion, the crystallization‐induced stress at glass–steel interface. We find that strong crystallization occurs at the operation temperature (700°C) far below the crystallization onset temperature measured by DSC. The structure origin of this anomalous crystallization is discussed in terms of structural heterogeneity of the three studied glasses. We determine the residual stress at the interface between the Ca‐containing glass and the steel after isothermal treatment at 700°C for 48 h, but this stress does not lead to falling off the glass layer from the steel. This indicates that this glass is a good candidate to be applied in SOFCs.

show abstract

“…It is worth mentioning here that apart from their own role changing (modifier ↔ former) behavior, TM cations also change the structural role of alkali cations. For instance, change in oxidation state of iron from Fe 3+ to Fe 2+ causes Na + and K + ions to change their role from charge balancers to network modifiers [19,20]. As a combined effect of these factors, diffusion of ions into each other during sintercrystallization is affected and variety of morphology is observed in the present samples due to variety of mixed valance states of corresponding TM ions.…”

Section: Densification and Morphologymentioning

confidence: 86%

Effect of transition metals (MO-TiO2, MnO2, Fe2O3, and ZnO) on crystallization and electrical conductivity of SiO2–CaO–Na2O–P2O5-based glass-ceramics

Danewalia

Khan

Dhillon

et al. 2020

Ionics

View full text Add to dashboard Cite

Various glasses are synthesized by melt quench technique. The addition of transition metal (TM) oxides into glasses paves the light on their crystallization and sinterability. The formation of different crystalline phases and their microstructures significantly influenced the conduction mechanism in these glass-ceramics. ZnO seemed to act as glass modifier, while TiO 2 appears to act as glass former in the present glasses. Other two TM oxides might have played a role as intermediate oxides. The present glassceramics are mixed conductors (ionic+electronic). MnO 2 -contained sample shows highest electrical conductivity while Fe 2 O 3contained sample show lowest conductivity. The observed results are interpreted on the basis of structural differences of the samples.

show abstract

Reduction‐Induced Inward Diffusion and Crystal Growth on the Surfaces of Iron‐Bearing Silicate Glasses

Cited by 14 publications

References 31 publications

Mixed alkaline‐earth effect on the mechanical and rheological properties of Ca–Mg silicate glasses

Mixed alkaline‐earth effect on the mechanical and rheological properties of Ca–Mg silicate glasses

Structure, crystallization, and performances of alkaline‐earth boroaluminosilicate sealing glasses for SOFCs

Effect of transition metals (MO-TiO2, MnO2, Fe2O3, and ZnO) on crystallization and electrical conductivity of SiO2–CaO–Na2O–P2O5-based glass-ceramics

Contact Info

Product

Resources

About