In and Si distribution in synthetic opals

An X-ray photoelectric absorption by samples of synthetic opals (SO) loaded by In and Si has yielded filler distribution profiles over thickness. The SO+In sample exhibited a uniform filling of SO voids throughout the sample thickness (on average, 16.9% of each large void). The SO+Si sample, besides the near-surface region where large voids are completely filled, revealed a region with variable Si concentration in the SO, where the Si content decreases linearly down to a depth where pure SO is found. Fiz. Tverd. Tela (St. Petersburg) 40, 1373–1375 (July 1998)