High Resolution XPS Spectrum of Calcite (CaCO3)

Calcite is a common component of soil and a natural mineral sometimes found in the form of large high quality single crystals. The interactions of calcite with ions in groundwater affect their transport in the environment. Consequently, understanding the surface chemistry of calcite is important for environmental remediation research. The measurements reported here were conducted to provide high quality valence band and core level spectra of the clean calcite surface and for comparison with data collected on an older instrument with lower spatial and energy resolution. A single crystal was broken in vacuum to expose the (101¯4) plane of rhombohedral calcite (CaCO3) for XPS analysis. Survey and multiplex spectra were collected under standard operating conditions with a Perkin Elmer Physical-Electronics 5600 spectrometer using monochromatic Al Kα x rays. An electron flood gun was used to control surface charging during the measurements.