Ultramarine, Lazurite and Sodalite Studied by Positron Annihilation and EPR Methods

• Authors: A. Baranowski , M. Dębowska , K. Jerie , A. Jezierski , M. Sachanbiński
• Languages of publication: EN

Abstracts

EN

Studies of positron annihilation accompanied by EPR technique were undertaken for sodalite and lazurite and their synthetic counterparts (syn­thetic sodalite and ultramarines). Results of measurements performed by two techniques of positron annihilation spectroscopy (angular correlation of annihilation radiation, ACAR, and positron annihilation lifetime) revealed the undoubted influence of free radicals on positron annihilation mechanism but both inhibition of positronium formation by them and the effect of filling cages ought to be taken into account. The distinct differences between ACAR curves for sodalites, lazurites and ultramarines probably reflect the presence of different radicals in their cages and chemical heterogeneity as well as the disorder in Al, Si-site ordering in case of ultramarines. Comparison of the results of ACAR measurements with the ones of the EPR studies indicates that there is correspondence between them. Similarly to three families of the ACAR curves, different likes of EPR lines were obtained for three groups of samples; sodalites, lazurites and ultramarines. It is possible that the an­nihilation of positrons takes place mainly with unpaired electrons recorded by the EPR technique.

Keywords

EN

71.60.+z; 78.70.-g; 61.90.+d; 76.30.-v

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 1995
• Volume: 88
• Issue: 1
• Pages: 29-41

Dates

published

1995-07

Contributors

author

A. Baranowski

• Institute of Experimental Physics, Wrocław University, Maxa Borna 9, 50-204 Wrocław, Poland

author

M. Dębowska

• Institute of Experimental Physics, Wrocław University, Maxa Borna 9, 50-204 Wrocław, Poland

author

K. Jerie

• Institute of Experimental Physics, Wrocław University, Maxa Borna 9, 50-204 Wrocław, Poland

author

A. Jezierski

• Institute of Chemistry, Wrocław University, Joliot Curie 14, 50-383 Wrocław, Poland

author

M. Sachanbiński

• Institute of Geological Sciences, Wrocław University, Maxa Borna 9, 50-204 Wrocław, Poland