Epitaxial growth, morphology and temperature stability of quartzlike dioxide germanium crystals

The conditions and mechanisms of epitaxial growth of quartz-like a-GeO 2 crystals on quartz substrates using an evaporative-recirculation method are considered. Relatively homogenous a-GeO 2 crystals weighing up to 200 g are grown at a growth rate of up to 0.3 mm/day. It is established that molecular adhesion at the boundary between the quartz substrate and the overgrown layer of a-GeO 2 cannot prevent its transition to a stable poorly soluble rutile-like phase. This makes it impossible to grow high-germanium quartz single crystals industrially using a mixture of quartz and quartz-like a-GeO 2 as a nutrient. However, this process can be implemented if other more soluble germanium-containing compounds, such as quartz-like Si-containing germanium-oxide, are found.