NMR of surfaces: sub-monolayer sensitivity with hyperpolarized 129Xe

A typical laboratory single crystal of 1 cm2 surface area has about 1015 adsorption sites on the surface. The current paper shows that NMR signals can be obtained from sub-monolayer amounts of 129Xe adsorbates. For this, less than 1015 atoms of hyperpolarized 129Xe were studied in gaseous and condensed form in single shot experiments. The highest polarization achieved so far is 0.7. Analysis of the results shows that spectra from 1013 atoms can be obtained in reasonable time, thus opening single crystal surfaces to NMR investigations with conventional spectrometers.