Calcium molybdate

Calcium molybdate - isotopically-enriched Calcium molybdate monocrystal (CMO). Chemical formula: 40Ca100MoO4. Method for the production - the Czochralski method. It is designed for the research of neutrinoless double-beta decay (0ν2β) as an element of a cryogenic scintillation detector. This 0ν2β study is aimed at solving the problem of determination of the neutrino mass. Calcium molybdate crystal is grown of high-purity initial powder in the high-frequency heating unit by the Czochralski method. This method is universal for growing high-quality scintillation monocrystals, to which Calcium molybdate belongs. Melting temperature of Calcium molybdate (Tm = 1445°C) allows to grow crystals in air atmosphere, using a platinum crucible (Tm = 1769°C). At room temperature and atmospheric pressure, СМО monocrystals have a scheelite-type structure (tetragonal system, space-group I41/a). In the СМО structure there are isolated anionic [MoO4]2– tetrahedra that are interconnected by Ca2+ ions, surrounded by eight ions of opposite signs. At Fomos-Materials the process of monocrystals growing consists of two stages (so called double recrystallization process). The recrystallization process allows to reduce the content of radioactive impurities in СМО monocrystals. After completion of growth, monocrystals are annealed to relieve mechanical stresses. СМО monocrystals grown in this way, have a mass of ~0.55 kg, a diameter of up to 49 mm and a total length of up to 110 mm.