Fourier transform NMR at single crystal surfaces — 6Li on Ru(001)

NMR was performed on lithium adsorbates (10−5 of a monolayer) on a ruthenium single crystal surface. For the first time, free induction decay and spin echo measurements were performed, yielding the transverse relaxation times T2∗ and T2. The experiments utilize highly polarized adsorbates and a new beam-foil detection scheme, with single photon counting and phase coherent summation. A short T2 time of 17 ms is found and contrasted with the much longer T1 time of 760 ms under conditions where the adsorbate is highly mobile. The reduced dimensionality of the system is the probable cause for this effect.