Potassium self-diffusion in a K-rich single-crystal alkali feldspar

Hergemöller F., Wegner M., Deicher M., Wolf H., Brenner F., Hutter H., Abart R., Stolwijk N.

Research article (journal)

Abstract

The paper reports potassium diffusion measurements performed on gem-quality single-crystal alkali feldspar in the temperature range from 1169 to 1021 K. Natural sanidine from Volkesfeld, Germany was implanted with 43K at the ISOLDE/CERN radioactive ion-beam facility normal to the (001) crystallographic plane. Diffusion coefficients are well described by the Arrhenius equation with an activation energy of 2.4 eV and a pre-exponential factor of 5 x 10-6 m2/s, which is more than three orders of magnitude lower than the 22Na diffusivity in the same feldspar and the same crystallographic direction. State-of-the-art considerations including ionic conductivity data on the same crystal and Monte Carlo simulations of diffusion in random binary alloy structures point to a correlated motion of K and Na through the interstitialcy mechanism.

Details zur Publikation

Publisher:
Pages: 7
Release year: 2016
Publishing company: Springer Verlag
Language in which the publication is written: English
Link to the full text: http://link.springer.com/article/10.1007/s00269-016-0862-1