Cation field strength effects on high pressure aluminosilicate glass structure: Multinuclear NMR and La XAFS results

Kelsey, Kimberly E.; Stebbins, Jonathan F.; Singer, David M.; Brown, Gordon E.; Mosenfelder, J. L.; Asimow, Paul D.

doi:10.1016/j.gca.2009.03.040

Cited by 88 publications

(147 citation statements)

References 66 publications

Supporting

Mentioning

132

Contrasting

Order By: Relevance

“…3C). The pressure-induced changes in X NBO are also more significant with increasing cation field strength (e.g., charge∕ionic radius) for the networkmodifying cations at the constant degree of polymerization at 1 atm (27,40) (Fig. 3D).…”

Section: Resultsmentioning

confidence: 96%

“…Uncertainties in P XNBO¼0 for most melts are smaller than 0.5 GPa but increase with increasing P XNBO¼0 (e.g., approximately 1.5 GPa for NS3 melts and approximately 2.5 GPa for NS2 melts; see SI Appendix). P XNBO¼0 accounts for the observed trend in the effect of composition on ð∂X NBO ∕∂PÞ T and thus decreases with an increase in the alkali∕silica ratio and cation field strength in silicate glasses (27,40). Ranges for P XNBO¼0 in melts is similar to the pressure ranges where melts are denser than solids, forming trapped melts in the early Earth (1).…”

Section: O-17mentioning

confidence: 87%

“…The simple predictive NBO fraction in the melt, if available, could be useful to yield the microscopic origins of melt properties. The advent of high-resolution, element-specific, multinuclear NMR techniques such as triple quantum magic angle spinning (3QMAS) NMR allows us to obtain previously unknown details of the pressure-induced structural changes in multicomponent melts at high pressure (23,(27)(28)(29). Quaternary Ca-Na aluminosilicate (CNAS) melts is a model system for slab-driven magmatic melts and midocean ridge basalts (MORBs) composition melts in the Earth's interior (30,31) and provides insights into the structure of complex primordial melts and magmatic reservoirs.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Lee

2011

Proc. Natl. Acad. Sci. U.S.A.

114

View full text Add to dashboard Cite

Pressure-induced changes in properties of multicomponent silicate melts in magma oceans controlled chemical differentiation of the silicate earth and the composition of partial melts that might have formed hidden reservoirs. Although melt properties show complex pressure dependences, the melt structures at high pressure and the atomistic origins of these changes are largely unknown because of their complex pressure-composition dependence, intrinsic to multicomponent magmatic melts. Chemical constraints such as the nonbridging oxygen (NBO) content at 1 atm, rather than the structural parameters for melt polymerization, are commonly used to account for pressure-induced changes in the melt properties. Here, we show that the pressure-induced NBO fraction in diverse silicate melts show a simple and general trend where all the reported experimental NBO fractions at high pressure converge into a single decaying function. The pressure-induced changes in the NBO fraction account for and predict the silica content, nonlinear variations in entropy, and the transport properties of silicate melts in Earth's mantle. The melt properties at high pressure are largely different from what can be predicted for silicate melts with a fixed NBO fraction at 1 atm. The current results with simplicity in melt polymerization at high pressure provide a molecular link to the chemical differentiation, possibly missing Si content in primary mantle through formation of hidden Si-rich mantle reservoirs. E arly in Earth history, during the magma-ocean phase, the chemical differentiation of the silicate earth, formation of core, and evolution of atmosphere were controlled by the properties of silicate melts at high pressure (1-6). Pioneering experimental studies show that these thermodynamic and transport properties relevant to the chemical evolution of the Earth vary nonlinearly with changes in pressure (7-9). For instance, the solubility of Ar into melts increases with increasing pressure and then decreases drastically with a further increase in pressure, with data suggesting a strong composition dependence (7,10,11). Similarly, complex behaviors were reported for the diffusivity and viscosity of silicate melts at high pressure (8). Although the trend in the silica activity in the melts at high pressure is not known, phase relations of mantle melts and minerals imply varying activity coefficients of the oxide in silicate melts with changes in pressure (12)(13)(14). Changes of up to two orders of magnitude in the element partitioning coefficient between melts and crystal/coexisting phases have been reported stemming mostly from the effect of the melt composition, constraining the fate of radioactive nuclides in the Earth's interior (15-18).The key to understanding these nonlinear changes in melt properties with pressure is the melt structure at high-pressure in a short-(e.g., coordination number) to medium-range scale (19)(20)(21). While recent progress in mineral physics provides the link between the macroscopic properties and the structures of...

show abstract

Section: Resultsmentioning

confidence: 96%

Section: O-17mentioning

confidence: 87%

mentioning

confidence: 99%

See 1 more Smart Citation

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Lee

2011

Proc. Natl. Acad. Sci. U.S.A.

114

View full text Add to dashboard Cite

show abstract

“…High-coordinated Si has been previously reported in high-pressure silicate glasses (Xue et al 1989(Xue et al , 1991Stebbins and Poe 1999;Allwardt et al 2004), and high-coordinated Al has been observed using various techniques in aluminosilicate glasses Yarger et al 1995;Li et al 1995;Poe et al 2001;Lee et al 2006;Allwardt et al 2005aAllwardt et al , 2005bKelsey et al 2009). However, in aluminosilicate glasses the Al apparently changes coordination more readily than does the Si and, to date, high-coordinated Si has not been directly observed in high-pressure aluminosilicate glasses (Yarger et al 1995;Allwardt et al 2007;Kelsey et al 2009), although it has been inferred from 17 O 3QMAS NMR (Lee 2004). It has been hypothesized that if both Al and Si are present in a glass, the Al will change coordination number instead of the Si because Al is better charge balanced with 5 or 6 oxygen ions than is Si and has a slightly larger cation radius.…”

mentioning

confidence: 89%

“…In aluminosilicate glasses, it appears that the dominant, recovered structural change around the Si cations involves the decrease in Si-O-(Si,Al) bond angles * E-mail: kkelsey@stanford.edu instead of an increase in coordination. Composition strongly influences the amount of high-coordinated Al and Si generated: variations in both NBO/T ratios and in the field strength of the modifier cations are known to be especially important (Xue et al 1991;Allwardt et al 2005b;Kelsey et al 2009). …”

mentioning

confidence: 99%

Simultaneous aluminum, silicon, and sodium coordination changes in 6 GPa sodium aluminosilicate glasses

Kelsey

Stebbins

Mosenfelder

et al. 2009

American Mineralogist

View full text Add to dashboard Cite

We present the first direct observation of high-coordinated Si and Al occurring together in a series of high-pressure sodium aluminosilicate glasses, quenched from melts at 6 GPa. Using 29Si MAS NMR, we observe that a small amount of Al does not have a significant effect on the amount of V Si or VI Si generated, but that larger Al concentrations lead to a gradual decrease in both these species. Na isotropic chemical shifts indicate decreases in the mean Na-O bond lengths with increasing pressure, which are more dramatic at higher Al contents. Recovered glass densities are about 10 to 15% greater than those of similar ambient pressure samples. However, the density increases due to the combined coordination changes of Al and Si are estimated to total only about 1 to 2%, and are roughly constant with composition despite the large effects of Al content on the individual coordinations of the two cations. Thus, effects of other structural changes must be significant to the overall densification. Apparent equilibrium constants for reactions involving the generation of high-coordinated species show systematic behavior, which suggests an internal consistency to the observed Si and Al coordination number shifts.

show abstract

Structural Origins of BaF₂/Ba_{1 −}_xR_xF_{2 +}_x/RF₃ Nanocrystals Formation from Phase Separated Fluoroaluminosilicate Glass: A Molecular Dynamic Simulation Study

Zhao

Ren

et al. 2019

Advcd Theory and Sims

View full text Add to dashboard Cite

Fluoroaluminosilicate glass-ceramics with M 1 − x R x F 2 + x (M 2+ : Sr 2+ , Ba 2+ , R 3+ : rare earth ions) crystals are novel host materials for luminescence applications. However, the preparation of such materials is still a trial-error based approach due to the lack of detailed glass structure understanding. In this work, the authors study the phase separation and potential nanocrystal formation in a series of Ba 2+ and La 3+ containing fluoroaluminosilicate glasses by molecular dynamics (MD) simulations. Fluoride phase separation is observed from all simulated glass samples. With gradual LaF 3 to BaF 2 substitution, the cations enrichment changes from Ba 2+ , to Ba 2+ and La 3+ , and finally La 3+ in the fluoride-rich regions. Besides, the competition between Al 3+ and La 3+ in fluoride phase and the consequently redistribution of Al 3+ and Na + into oxide phase are observed, which can change the local environment of luminescent centers, affecting luminescence. An experimental support to this phenomenon is given. Therefore, MD simulation with effective potentials can be a practical method to study the structural origins of nanocrystal from fluoride phase separation as well as to study the structure-property relationship in fluoroaluminosilicate glass. The simulation driven glass structure and crystal phase exploration can thus become an effective method in designing glass-ceramics for luminescence and other applications.

show abstract

Cation field strength effects on high pressure aluminosilicate glass structure: Multinuclear NMR and La XAFS results

Cited by 88 publications

References 66 publications

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Simultaneous aluminum, silicon, and sodium coordination changes in 6 GPa sodium aluminosilicate glasses

Structural Origins of BaF₂/Ba_{1 −}_xR_xF_{2 +}_x/RF₃ Nanocrystals Formation from Phase Separated Fluoroaluminosilicate Glass: A Molecular Dynamic Simulation Study

Contact Info

Product

Resources

About

Cation field strength effects on high pressure aluminosilicate glass structure: Multinuclear NMR and La XAFS results

Cited by 88 publications

References 66 publications

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Simplicity in melt densification in multicomponent magmatic reservoirs in Earth’s interior revealed by multinuclear magnetic resonance

Simultaneous aluminum, silicon, and sodium coordination changes in 6 GPa sodium aluminosilicate glasses

Structural Origins of BaF2/Ba1 −xRxF2 +x/RF3 Nanocrystals Formation from Phase Separated Fluoroaluminosilicate Glass: A Molecular Dynamic Simulation Study

Contact Info

Product

Resources

About

Structural Origins of BaF₂/Ba_{1 −}_xR_xF_{2 +}_x/RF₃ Nanocrystals Formation from Phase Separated Fluoroaluminosilicate Glass: A Molecular Dynamic Simulation Study