Design Rules for Ce-Activated Scintillating Radiation Detection Materials: Compromises Between Luminosity and Stopping Power

This paper presents new development methods for property-screening design rules, using structure-property relationships for two fundamental properties of activated scintillating based gamma radiation detection-luminosity and stopping power. The first and most evident goal in developing screening models of luminosity and stopping power, as indicated by the weight and electron densities, is to obtain new candidate cerium scintillating materials. However, a second and more strategic goal is to extract design rules, which define the structural limitations on materials consistent with desirable detector properties. These design rules are based on our capability to predict the luminescence and stopping power of a material from a set of structural descriptors. Predictive models are generated using statistical multiple linear regression over a set of 24 descriptors. We find that within a set of ten cerium-doped scintillator materials we can quantitatively predict luminosity with a correlation coefficient of ~0.94 based on 4 of the 24 descriptors, improving to ~0.99 with 6 descriptors; and electron density to ~0.99 with 3 descriptors. Furthermore, we show in this circumstance that the luminosity and stopping power are only nominally related. In particular, luminosity depends largely on matrix valence electron properties and their coupling to activator sites-properties that do not require high atomic masses or atomic numbers per se, requirements for high stopping power.