Five new isostructural cubic thiogermanates with the formula A 0.5M1.75GeQ4 (A=Ag, Cu, Na; M=Pb, Eu; Q=S, Se) have been prepared by direct combination of stoichiometric amounts of the elements. The compounds crystallize in the noncentrosymmetric space group I-43d with Z=16 and a=14.0291(5) Å for Ag0.5Pb1.75GeS 4, a=14.5949(19) Å for Ag0.5Pb 1.75GeSe4, a=13.9491(14) Å for Ag 0.5Eu1.75GeS4, a = 13.8145(9) Å for Cu0.5Pb1.75GeS4 and a = 14.662(4) Å for Na0.5Pb1.75GeSe4. The adopted structure is similar to that of Ba3CdSn2S8, and features tetrahedral [GeQ4]4- building blocks. These compounds are semiconductors with energy gaps (Eg) ranging from 1.48 to 1.83 eV.
|Number of pages||9|
|Journal||Solid State Sciences|
|Publication status||Published - May 1 2004|
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics