Materials for transparent ceramics: Physical issues and technological solutions

The present work is focused on inherent optical properties, governed by composition and the state of the crystal lattice, and on their interference with conditions of the microstructural optimization of transparent ceramics (e.g. the dependence of the tolerable pore size or grain size on the refractive index). Starting with the general difference between the dispersive performances n(lambda) of glasses and transparent ceramics, examples will demonstrate the use of compositional changes for tuning the relationship of index, Abbé number, and anomalous dispersion. Perowskites and cubic zirconia are known candidates for such developments, but their mechanical strength is low. Therefore, physical conditions are investigated for bringing translucent tetragonal ZrO2 to transparency. Another field of increasing interest is transparency at extreme wave lengths. As an example, the present investigation addresses transmittance close to the UV absorption edge.