Lattice location of trace elements within minerals and at their surfaces with X-ray standing waves

Science  09 Sep 1994:
Vol. 265, Issue 5178, pp. 1555-1557
DOI: 10.1126/science.8079168


The x-ray standing waves generated by dynamical Bragg diffraction were used to directly measure lattice locations of trace elements within and at the surface of a mineral single crystal. These high-precision measurements were made on natural Iceland spar calcite cleaved along the (1014) plane and reacted with a dilute aqueous lead solution. Within the bulk crystal, naturally occurring trace manganese was found within (1014) planes, consistent with its substitution for calcium. At the crystal surface, sorbed lead was found to be highly ordered and mostly within (1014) planes. This demonstrates a powerful application of synchrotron radiation in the earth and environmental sciences.