Photoabsorption of NaCl clusters at the Na K-edge: Development of the bond length with the cluster size

Photoabsorption spectra of free and deposited NaCl clusters at the Na K-edge are presented. The absorption spectra were recorded using the yield of photoelectrons and cluster ions. Above the K-shell ionization limit, multi-scattering-type oscillations could be identified which allow the determination of bond length in the cluster. The variation of the bond length with cluster size is in reasonable agreement with model calculations, assuming a Coulomb interaction and a Born–Meyer type repulsion of the ions.