The Luminescence of Tb3+ in Borates of the Composition X[sub 2]Z(BO[sub 3])[sub 2] (X = Ba, Sr, Ca; Z = Ca, Mg)

Abstract

Four new borates of the formula , are described. is tetragonal, and is hexagonal and isomorphous with the mineral buetschliite. and are related to buetschliite but their diffraction patterns point to a crystallographic system of lower symmetry. All four borates are good host lattices for Tb³⁺ luminescence. The maximum quantum efficiencies are approximately 75% and are strongly influenced by the method of charge compensation used. The emission spectrum shows the usual being the strongest. The temperature dependence of the emission is good.