Refractive index and surface layers of ceramic (Pb,La)(Zr,Ti)O_3 compounds

Refractive indexes of the (Pb,La)(Zr,Ti)O(3) system are determined by minimum deviation for eight ceramic compounds over the 400-750-nm wavelength range and for two compounds over the 25-150 degrees C temperature range. The index of one compound (10/65/35) is reported to 2600 nm. Ellipsometric measurements show the presence of a low-index surface layer on these ceramics. Such layers, whose origin is not determined, have influenced previous index measurements based on reflection techniques.