Potassium tetragermanate gel (K2O 4GeO2) was synthesized by hydrolytic polycondensation of germanium ethoxide with potassium ethoxide in alcoholic medium. The crystallization behavior of the gel, examined by differential thermal analysis and X-ray diffraction, is reported and discussed. Potassium tetragermanate gel crystallizes in two steps. At about 593°C, metastable K4Ge9O20 crystals are formed as the major crystalline phase with a small amount of K2Ge4O9 crystals. At higher temperatures, metastable K4Ge9O20 are converted to the thermodynamically stable K2Ge4O9 phase. These results are compared with those of conventionally prepared glass of the same composition.
GEL SYNTHESIS AND CRYSTALLIZATION OF POTASSIUM TETRAGERMANATE GLASS POWDERS
CATAURO, Michelina;
1999
Abstract
Potassium tetragermanate gel (K2O 4GeO2) was synthesized by hydrolytic polycondensation of germanium ethoxide with potassium ethoxide in alcoholic medium. The crystallization behavior of the gel, examined by differential thermal analysis and X-ray diffraction, is reported and discussed. Potassium tetragermanate gel crystallizes in two steps. At about 593°C, metastable K4Ge9O20 crystals are formed as the major crystalline phase with a small amount of K2Ge4O9 crystals. At higher temperatures, metastable K4Ge9O20 are converted to the thermodynamically stable K2Ge4O9 phase. These results are compared with those of conventionally prepared glass of the same composition.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
