Two diffusion pathways in quartz: A combined UV-laser and RBS study

P. L. Clay, E. F. Baxter, D. J. Cherniak, S. P. Kelley, Jay Thomas, E. B. Watson

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The diffusive behavior of argon in quartz was investigated with three analytical depth profiling methods: Rutherford Backscattering Spectroscopy (RBS), 213nm laser ablation, and 193nm (Excimer) laser ablation on the same set of experimental samples. The integration of multiple depth profiling methods, each with different spatial resolution and sensitivity, allows for the cross-checking of methods where data ranges coincide. The use of multiple methods also allows for exploration of diffusive phenomena over multiple length-scales. Samples included both natural clear rock crystal quartz and synthetic citrine quartz. Laser analysis of clear quartz was compromised by poor coupling with the laser, whereas the citrine quartz was more easily analyzed (particularly with 193nm laser). Diffusivity measured by both RBS and 193nm laser ablation in the outermost 0.3μm region of citrine quartz are self-consistent and in agreement with previously published RBS data on other quartz samples (including the clear quartz measured by RBS in this study). Apparent solubilities (extrapolated surface concentrations) for citrine quartz are in good agreement between RBS, 213nm, and 193nm laser analyses. Deeper penetration of argon measured up to 100μm depth with the 213nm laser reveal contributions of a second, faster diffusive pathway, effective in transporting much lower concentrations of argon into the crystal interiors of both clear and citrine quartz. By assuming such deep diffusion is dominated by fast pathways and approximating them as a network of planar features, the net diffusive uptake can be modeled and quantified with the Whipple-LeClaire equation, yielding δDb values of 1.32×10-14 to 9.1×10-17cm3/s. While solubility values from the measured profiles confirm suggestions that quartz has a large capacity for argon uptake (making it a potentially important sink for argon in the crust), the slow rate of lattice diffusion may limit its capability to take up argon in shorter lived geologic environments and in experiments. In such shorter-lived systems, bulk argon diffusive uptake will be dominated by the fast pathway and the quartz lattice (including natural isolated defects that may also be storing argon) may never reach its equilibrium capacity.

Original languageEnglish (US)
Pages (from-to)5906-5925
Number of pages20
JournalGeochimica et Cosmochimica Acta
Volume74
Issue number20
DOIs
StatePublished - Oct 2010
Externally publishedYes

Fingerprint

Quartz
Rutherford backscattering spectroscopy
Argon
laser
spectroscopy
quartz
argon
Lasers
Laser ablation
ablation
Depth profiling
solubility
Solubility
crystal
Excimer lasers
diffusivity
defect
spatial resolution
penetration

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

Clay, P. L., Baxter, E. F., Cherniak, D. J., Kelley, S. P., Thomas, J., & Watson, E. B. (2010). Two diffusion pathways in quartz: A combined UV-laser and RBS study. Geochimica et Cosmochimica Acta, 74(20), 5906-5925. https://doi.org/10.1016/j.gca.2010.07.014

Two diffusion pathways in quartz : A combined UV-laser and RBS study. / Clay, P. L.; Baxter, E. F.; Cherniak, D. J.; Kelley, S. P.; Thomas, Jay; Watson, E. B.

In: Geochimica et Cosmochimica Acta, Vol. 74, No. 20, 10.2010, p. 5906-5925.

Research output: Contribution to journalArticle

Clay, PL, Baxter, EF, Cherniak, DJ, Kelley, SP, Thomas, J & Watson, EB 2010, 'Two diffusion pathways in quartz: A combined UV-laser and RBS study', Geochimica et Cosmochimica Acta, vol. 74, no. 20, pp. 5906-5925. https://doi.org/10.1016/j.gca.2010.07.014
Clay, P. L. ; Baxter, E. F. ; Cherniak, D. J. ; Kelley, S. P. ; Thomas, Jay ; Watson, E. B. / Two diffusion pathways in quartz : A combined UV-laser and RBS study. In: Geochimica et Cosmochimica Acta. 2010 ; Vol. 74, No. 20. pp. 5906-5925.
@article{a62ff601744c435688157629ac16bedc,
title = "Two diffusion pathways in quartz: A combined UV-laser and RBS study",
abstract = "The diffusive behavior of argon in quartz was investigated with three analytical depth profiling methods: Rutherford Backscattering Spectroscopy (RBS), 213nm laser ablation, and 193nm (Excimer) laser ablation on the same set of experimental samples. The integration of multiple depth profiling methods, each with different spatial resolution and sensitivity, allows for the cross-checking of methods where data ranges coincide. The use of multiple methods also allows for exploration of diffusive phenomena over multiple length-scales. Samples included both natural clear rock crystal quartz and synthetic citrine quartz. Laser analysis of clear quartz was compromised by poor coupling with the laser, whereas the citrine quartz was more easily analyzed (particularly with 193nm laser). Diffusivity measured by both RBS and 193nm laser ablation in the outermost 0.3μm region of citrine quartz are self-consistent and in agreement with previously published RBS data on other quartz samples (including the clear quartz measured by RBS in this study). Apparent solubilities (extrapolated surface concentrations) for citrine quartz are in good agreement between RBS, 213nm, and 193nm laser analyses. Deeper penetration of argon measured up to 100μm depth with the 213nm laser reveal contributions of a second, faster diffusive pathway, effective in transporting much lower concentrations of argon into the crystal interiors of both clear and citrine quartz. By assuming such deep diffusion is dominated by fast pathways and approximating them as a network of planar features, the net diffusive uptake can be modeled and quantified with the Whipple-LeClaire equation, yielding δDb values of 1.32×10-14 to 9.1×10-17cm3/s. While solubility values from the measured profiles confirm suggestions that quartz has a large capacity for argon uptake (making it a potentially important sink for argon in the crust), the slow rate of lattice diffusion may limit its capability to take up argon in shorter lived geologic environments and in experiments. In such shorter-lived systems, bulk argon diffusive uptake will be dominated by the fast pathway and the quartz lattice (including natural isolated defects that may also be storing argon) may never reach its equilibrium capacity.",
author = "Clay, {P. L.} and Baxter, {E. F.} and Cherniak, {D. J.} and Kelley, {S. P.} and Jay Thomas and Watson, {E. B.}",
year = "2010",
month = "10",
doi = "10.1016/j.gca.2010.07.014",
language = "English (US)",
volume = "74",
pages = "5906--5925",
journal = "Geochmica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier",
number = "20",

}

TY - JOUR

T1 - Two diffusion pathways in quartz

T2 - A combined UV-laser and RBS study

AU - Clay, P. L.

AU - Baxter, E. F.

AU - Cherniak, D. J.

AU - Kelley, S. P.

AU - Thomas, Jay

AU - Watson, E. B.

PY - 2010/10

Y1 - 2010/10

N2 - The diffusive behavior of argon in quartz was investigated with three analytical depth profiling methods: Rutherford Backscattering Spectroscopy (RBS), 213nm laser ablation, and 193nm (Excimer) laser ablation on the same set of experimental samples. The integration of multiple depth profiling methods, each with different spatial resolution and sensitivity, allows for the cross-checking of methods where data ranges coincide. The use of multiple methods also allows for exploration of diffusive phenomena over multiple length-scales. Samples included both natural clear rock crystal quartz and synthetic citrine quartz. Laser analysis of clear quartz was compromised by poor coupling with the laser, whereas the citrine quartz was more easily analyzed (particularly with 193nm laser). Diffusivity measured by both RBS and 193nm laser ablation in the outermost 0.3μm region of citrine quartz are self-consistent and in agreement with previously published RBS data on other quartz samples (including the clear quartz measured by RBS in this study). Apparent solubilities (extrapolated surface concentrations) for citrine quartz are in good agreement between RBS, 213nm, and 193nm laser analyses. Deeper penetration of argon measured up to 100μm depth with the 213nm laser reveal contributions of a second, faster diffusive pathway, effective in transporting much lower concentrations of argon into the crystal interiors of both clear and citrine quartz. By assuming such deep diffusion is dominated by fast pathways and approximating them as a network of planar features, the net diffusive uptake can be modeled and quantified with the Whipple-LeClaire equation, yielding δDb values of 1.32×10-14 to 9.1×10-17cm3/s. While solubility values from the measured profiles confirm suggestions that quartz has a large capacity for argon uptake (making it a potentially important sink for argon in the crust), the slow rate of lattice diffusion may limit its capability to take up argon in shorter lived geologic environments and in experiments. In such shorter-lived systems, bulk argon diffusive uptake will be dominated by the fast pathway and the quartz lattice (including natural isolated defects that may also be storing argon) may never reach its equilibrium capacity.

AB - The diffusive behavior of argon in quartz was investigated with three analytical depth profiling methods: Rutherford Backscattering Spectroscopy (RBS), 213nm laser ablation, and 193nm (Excimer) laser ablation on the same set of experimental samples. The integration of multiple depth profiling methods, each with different spatial resolution and sensitivity, allows for the cross-checking of methods where data ranges coincide. The use of multiple methods also allows for exploration of diffusive phenomena over multiple length-scales. Samples included both natural clear rock crystal quartz and synthetic citrine quartz. Laser analysis of clear quartz was compromised by poor coupling with the laser, whereas the citrine quartz was more easily analyzed (particularly with 193nm laser). Diffusivity measured by both RBS and 193nm laser ablation in the outermost 0.3μm region of citrine quartz are self-consistent and in agreement with previously published RBS data on other quartz samples (including the clear quartz measured by RBS in this study). Apparent solubilities (extrapolated surface concentrations) for citrine quartz are in good agreement between RBS, 213nm, and 193nm laser analyses. Deeper penetration of argon measured up to 100μm depth with the 213nm laser reveal contributions of a second, faster diffusive pathway, effective in transporting much lower concentrations of argon into the crystal interiors of both clear and citrine quartz. By assuming such deep diffusion is dominated by fast pathways and approximating them as a network of planar features, the net diffusive uptake can be modeled and quantified with the Whipple-LeClaire equation, yielding δDb values of 1.32×10-14 to 9.1×10-17cm3/s. While solubility values from the measured profiles confirm suggestions that quartz has a large capacity for argon uptake (making it a potentially important sink for argon in the crust), the slow rate of lattice diffusion may limit its capability to take up argon in shorter lived geologic environments and in experiments. In such shorter-lived systems, bulk argon diffusive uptake will be dominated by the fast pathway and the quartz lattice (including natural isolated defects that may also be storing argon) may never reach its equilibrium capacity.

UR - http://www.scopus.com/inward/record.url?scp=79952686302&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79952686302&partnerID=8YFLogxK

U2 - 10.1016/j.gca.2010.07.014

DO - 10.1016/j.gca.2010.07.014

M3 - Article

AN - SCOPUS:79952686302

VL - 74

SP - 5906

EP - 5925

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 20

ER -