Assembling a semiconductor quantum supralattice one atom at a time: Nonstoichiometric silver, sodium bromosodalites

The synthetic details and structural, vibrational, and optical properties of a series of novel silver, sodium bromohydrosodalites of the type (8 - p - 2n)Na,2nAg, (2 - p)Br-SOD, where p = 0-2, 2n = 0-8 are reported. These sodalites form a solid solution of empty β-cages interdispersed with Na_4-nAg_nBr clusters. Variations in p alter the mean distance between the clusters while changes in n shift the constituents of the clusters from those of an insulator to a semiconductor type. Far-infrared, ²³Na MAS-NMR, optical spectroscopy, and Rietveld refinement of high-resolution powder XRD data show that these materials offer the opportunity to manipulate the extent of collective electronic and vibrational interactions between monodispersed clusters in a perfectly crystalline host.