Optical properties of transparent nanocrystalline yttria stabilized zirconia

The optical properties of transparent nanocrystalline zirconia produced using a current activated method were characterized over the entire visible spectrum. The resolutions of the samples were characterized using standard resolution targets. All of the samples produced were found to have as high a resolution as detectable from the test, i.e., they are transparent not translucent. Transmission, reflectance, and absorption coefficients are reported for various wavelengths. The absorption coefficients were found to be highly dependent on processing time. Annealing experiments helped determine that oxygen vacancies (with free electrons) are the primary absorption centers in the visible wavelengths. In addition it was found that grain boundary cores or their associated defects do not contribute significantly to light absorption in the visible range. The lack of an influence of the grain boundary regions is discussed in terms of low oxygen vacancy concentration in the grain boundary space charge layer.