Interrelations between composition, structure, thermal stability, and chromatic characteristics of new NASICON-related solid solutions of Li1+xCrxZr2−x(PO4)3

In this contribution, formation and properties of full series of solid solutions of Li1+xCrxZr2−x(PO4)3 are discussed. Special attention is paid to interrelations between substitution degree x, resulting crystal structure, crystal field parameters, and colour hue of the samples. It is shown, that within the studied synthesis conditions, an increase of the substitution degree x in the solid solutions leads to structural change from triclinic (new NASICON-based modification) to orthorhombic SW type, while both end-members of the solid solutions are rhombohedral. Interrelations between the substitution degree x, thermal stability and particle size distribution are also discussed. The colour of the samples is explained by means of crystal field theory. It is shown, that the crystal field strength is controlled by the substitution degree x: with an increase of the substitution degree x crystal field strength shifts to higher energies and the resulting colouration changes from light pink via brown to bright green. Because of the excellent thermal stability of the samples as well as the wide range of colours, the Li1+xCrxZr2−x(PO4)3 series can be considered as attractive candidates for application as ceramic pigments.