Abstract: | It has been found that on exposure of specimens of synthetic opal to UV radiation, luminescence is excited in them (337 nm)
that has spectral maxima at 400 and 500 nm. Its duration at half-height of a pulse is 9 nsec, and there is a weak slow component
with τ ∼ 1 μsec. The spectrum and intensity of the luminescence depend on the duration of irradiation and temperature. The
luminescence bands revealed relate to two individual luminescence centers, namely: the shortwave one, caused by the luminescence
centers formed in the bulk of the opal, and the longwave one, due to those formed on the opal surface.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 622–626, September–October, 2005. |