Na4Ca(CO3)3: a novel carbonate analog of borate optical materials

Abstract

Carbonate optical materials currently attract a lot of interest as an unexplored alternative to borate ones. However, these two classes of compounds were believed to have quite different crystal chemistry, so that no systematic attempts were made to reproduce crystal structures of known borate optical materials in carbonates. Here we describe a novel Na₄Ca(CO₃)₃ cubic carbonate (Ia3d, a = 15.5770(5) Å), isostructural to borates of the NaBa₄(BO₃)₃ family known for their phosphor properties, and discuss further perspectives in the investigation of ‘borate-structured’ carbonate materials.