Results for aliovalent doping of CeBr₃ with Ca²⁺

Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr₃) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca²⁺) was used as a dopant to strengthen CeBr₃ without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca²⁺ dopant were grown, i.e., 1.9% of the CeBr₃ molecules were replaced by CaBr₂ molecules, to match our target replacement of 1 out of 54 cerium atoms be replaced by a calcium atom. Precisely the mixture was composed of 2.26 g of CaBr₂ added to 222.14 g of CeBr₃. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca²⁺-doped CeBr₃ exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr₃. The structural, electronic, and optical properties of CeBr₃ crystals were studied using the density functional theory within the generalized gradient approximation. Calculated lattice parameters are in agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr₃, including the dielectric function, were calculated.