Preparation and Examination of Some Double Tungstates and Molybdates

There are several reports [1–5] on the production of single crystals of double tungstates and molybdates of the alkalis and rare earths of type MILnIII (WO4)2, where MI = Li, Na, K; some of them have been used as laser materials [2]. Double tungstates and molybdates of the alkali metals can be made with the lighter elements of group III, such as Al and Ga, but no systematic study appears to have been made on these. The compound NaAl(WO4)2 has been made as a ceramic [6], while single crystals of NaIn(WO4)2 have been grown from solution in a melt as source materials for masers [7].