title: Flux growth of hexagonal bipyramidal ruby crystals.
abstract: Hexagonal bipyramidal ruby (Al2O3:Cr) crystals were easily grown by the evaporation of MoO3 flux isothermally. The crystal growth was conducted by heating a mixture of solute (Al2O3 + 0.5 mass% Cr2O3) and flux (MoO3) at 1100 degrees C, followed by holding the solution at this temperature for 5 h. The ruby crystals obtained lengths up to 1.8 mm and widths up to 1.7 mm and were transparent-red. Their form was a bipyramid bounded by well-developed {113} faces. Molybdenum trioxide was found to be a very suitable flux for growing bipyramidal ruby crystals.
authors.affiliation: Department of Environmental Science and Technology, Faculty of Engineering, Shinshu University, Nagano 380-8553, Japan. oishish@gipwc.shinshu-u.ac.jp
authors.forename: Shuji
authors.initials: S
authors.lastname: Oishi
authors.forename: Katsuya
authors.initials: K
authors.lastname: Teshima
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kondo