Non-hydrolytic sol-gel synthesis, properties, and high-pressure behavior of gallium molybdate

A new material, Ga2Mo3O12, was prepared for the first time using non-hydrolytic sol-gel chemistry. Rietveld analysis of variable temperature X-ray diffraction data showed that this compound crystallizes in the monoclinic Sc2W3O12 structure, and that it displays positive thermal expansion up to its decomposition temperature of 650 degrees C. No phase transitions were observed in this temperature range. The high-pressure behavior was investigated with an in situ synchrotron diffraction study. Reversible phase transitions to new monoclinic structures occurred at approximately 3.2 and 4.1 GPa. In addition, irreversible amorphization was observed above 8 GPa.