Compositions are generally provided that include an oxyfluoride compound. In one embodiment, the oxyfluoride compound has the formula: NaCa.sub.2xA.sub.xGeO.sub.4zF.sub.1yN.sub.z where A is Ba, Sr, or a mixture thereof; 0.01x0.1; 0y0.2; and 0z0.1. Methods of forming such compounds are also generally provided.