ALKALI SURFACE CONCENTRATION AT ELEVATED TEMPERATURES.

John F. Kelso, Carlo G. Pantano

Research output: Contribution to conferencePaperpeer-review

Abstract

The alkali concentration in the surface monolayer of Na//2O multiplied by (times) 3SiO//2 and K//2O multiplied by (times) 3SiO//2 glasses was measured at elevated temperatures with ion scattering spectroscopy (ISS). At temperatures in and below the glass transformation range, the surface composition was time-dependent. In general, the alkali was depleted in the surface monolayer due to evaporation; the alkali depletion at the surface increased with decreasing temperature. These data could be mathematically modeled in terms of a surface reaction (desorption) term and a diffusion term. At temperatures above the transformation range, the alkali concentration in the surface reached an apparent steady-state value which was about 90% of the bulk concentration. It is suggested that surface tension, surface stress and convection may also influence the high temperature surface composition.

Original languageEnglish (US)
Pages391-398
Number of pages8
StatePublished - Dec 1 1986

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Fingerprint Dive into the research topics of 'ALKALI SURFACE CONCENTRATION AT ELEVATED TEMPERATURES.'. Together they form a unique fingerprint.

Cite this