用铜物理显影的多级放大成像过程Ⅲ.影像中铜和银的分布及明胶对Au3+的还原

本文研究了铜物理显影后影像中铜和银的分布以及在非影像区明胶对Au³⁺的还原作用。铜含量随着影像深度的增加而增加,银含量却随着深度的增加而减少。Ag3d结合能向低值位移说明影像内部的银处于单原子和多原子的混合状态,但是影像表面的银却为单原子状态,如果铜物理显影进行得足够长,铜最终会将银全部遮盖。在这以后的铜物理显影是铜的自催化过程,样片浸入氯金酸溶液中后,非影像区中吸收的氯金酸量大大高于影像区,因而铜的沉积速度在非影像区也比影像区大得多。明胶能还原Au³⁺.还原过程可分为两步:第一步由Au³⁺还原成Au⁺,这一步在室温下是快反应;第二步由Au⁺还原成金,这个反应比较慢,Au⁺和Au在物理显影中可作为催化核,使铜在非影像区沉积。

AN IMAGING PROCESS WITH MULII-STAGEAMPLIFlCATION BY COPPER PHYSHICAL DEVELOPMENT III.THE DISTRIBUTION OF COPPER AND SILVER WITHIN THE FINAL IMAGE AND THE REDUCTION OF Au3+ BY GELATIN IN NON-IMAGE AREA

The distribution of copper and silver within the final image obtained by copper phys-ical development and the reduction of Au³⁺ by gelatin in non-image area were studied.Itwas indicated that the copper content increases with the increase of depth,whereas the sil-ver content decreases with the increase of depth,The shift of the bind energy of Ag3d to alow value shows that the silver in the interior of the image is in a mixed state of monoatomsand polyatoms,but the silver at the image surface is exclusively in a monoatomic state.Ifthe time of copper physical development is long enough,copper will completely cover silver.From then on the copper physical development continues because of the autocatalysis ofnewly formed copper.It was shown that much more chloroauric acid was absorbed in thenon-image area and hence the deposition speed of copper was much faster than that in theimage area.Gelatin can reduce Au³⁺.The reduction process might be divided into twosteps.The first step, which is fast at the room temperature,is the formation of Au⁺,andthe second step,which is relatively slow,is the formation of gold.Au⁺ and gold mightact as catalytic nuclei during the copper physical development depositing copper in thenon-image area.