Low-temperature synthesis of freudenbergite-type titanate bronzes from metal halides, crystal growth from molybdate flux, and crystal structure determination of Na sub(1.84)Zn sub(0.92)Ti sub(7.08)O sub(16)

A new precipitation method to synthesize freudenbergite-type phases from metal halides has been developed, and titanate bronzes of the general formula Na sub(x)M sub(y)Ti sub(8-y)O sub(16) with M = Fe, Zn were obtained as micro-crystalline powders (Fe: orange-yellow, Zn: colorless). The crystal structures were refined based on synchrotron X-ray data using the Rietveld method. Single crystals of the new compound Na sub(1.848(8))Zn sub(0.924(3))T i sub(7.076(3))O sub(16) were grown from molybdate flux, and its crystal structure was determined (s.g. C2/m, No. 12, a = 1230.2(2) pm, b = 381.94(4) pm, c = 650.2(2) pm, and beta = 107.09(2)[degrees]). It is isostructural to the Fe-containing freudenbergite-type phase. Absorption spectra from diffuse reflection measurements are shown.