MEASUREMENTS OF SPECTRAL TRANSMITTANCE OF POROUS CERIUM DIOXIDE IN THE RANGE 900-1,700 NM

摘要

Overall transmittance of porous cerium dioxide is measured in the spectral range of 900-1700 nm using dispersive spec troscopy. Dense and porous samples of cerium dioxide with av erage porosities of 0.08 and 0.72, respectively, are investigated. The transmittance of both sample types increases with decreas ing thickness, and this trend is more pronounced for the dense samples. The on-average spectrally increasing transmittance of the dense samples is attributed to the decreasing absorption by bulk cerium dioxide with radiation wavelength. The trans mittance of the porous samples, on the other hand, remains a constant over the spectrum. Porous samples attenuate radiation stronger than the dense samples at any wavelength in the consid ered range, and it is hypothesized that this effect is due to more intense scattering. Sharp local variations of the transmittance are observed for both sample types.