Direct Synthesis of New Zircon‐Type ZrGeO 4 and Zr(Ge,Si)O 4 Solid Solutions

A new phase of ZrGeO 4 was hydrothermally synthesized from a mixture of ZrOCl 2 solution and GeO 2 powder at 240°C. X‐ray diffractometry patterns of synthesized ZrGeO 4 particles, which had better crystallinity than ZrSiO 4 particles prepared by the same process from ZrOCl 2 and tetraethoxysilane, could be indexed for a zircon‐type tetragonal structure, having a 0 = 0.6694(0) and c 0 = 0.6265(7) nm. The c / a ratio of synthesized ZrGeO 4 (0.9360) was larger than that of ZrSiO 4 (0.9054). Solid solutions with zircon‐type structure over the whole composition range in the ZrGeO 4 ‐ZiSiO 4 system were also directly synthesized through the same solution route. The secondary particle size of zircon‐type Zr(Ge,Si)O 4 solid solutions decreased, and its morphology gradually changed from octahedron‐like to blood‐red cell‐like with decreased GeO 2 content.