METHOD FOR PRODUCING MONOCRYSTALS OF MONOCLINIC HAFNIUM DIOXIDE Russian patent published in 2017 - IPC C30B25/00 C30B25/08 C30B29/16 C30B29/64 C23C16/40 C09K11/08 H01S3/16 B82B3/00 B82Y5/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: method comprises interaction of metallic hafnium placed inside a quartz ampoule serving as an oxygen source with carbon tetrafluoride, which fills the ampoule after its evacuation, and heating of the sealed ampoule with the above mentioned reagents at a temperature of not more than 1200°C for at least 24 hours, while the metallic hafnium is placed in a quasi hermetic cartridge made of nickel or thermally expanded graphite with an opening of not more than 2-6 mm² and placed inside the quartz ampoule, which is filled with carbon tetrafluoride to a pressure of not more than 250 torr.

EFFECT: possibility of obtaining monocrystals of monoclinic hafnium dioxide of large size due to slow growth as a result of limited diffusion of gaseous hafnium fluorides through a small-diameter hole in a cartridge made of a material inert to carbon tetrafluoride and hafnium tetrafluoride.

2 cl, 2 dwg, 3 ex