High‐Temperature Crystallization, Composition, Structure, and Certain Properties of Rare‐Earth Gallium Borates

Abstract

Abstract Solution‐melts based on PbF 2 —B 2 O 3 and Bi 2 O 3 —B 2 O 3 were used in studying the stability regions and for growth, by way of spontaneous crystallization, of crystals up to 3 mm in size of twelve compounds having the general formula RGa 3 (BO 3 ) 4 . All of these compounds are isostructural with carbonate mineral huntite. Their composition is highly dependent on that of the crystallization medium. The facing of the crystals is characterized by a small number of simple forms {10 1 1}, {11 2 0}, {2 1 1 0}, and less frequently {02 2 1}, {0112}, {40 4 1}. The examined parameters include the IR spectra, luminescence spectra, heat of formation from oxides, harness (6 to 8 units on the Mohs scale) and others.