University of Pardubice Faculty of Chemical Technology

University

Employees
|
Students
Česky

Publication detail

Surface treatment of optical materials evaluation of process

Authors: Samsonova Ekaterina | Vilkova E. Yu | Timofeev O. V.

Year: 2022

Type of publication: ostatní - přednáška nebo poster

Page from-to: nestránkováno

Titles:

Language	Name	Abstract	Keywords
eng	Surface treatment of optical materials evaluation of process	High requirements are imposed on optical elements with respect to the quality of their surface, both in terms of purity and in terms of the geometric shape of the surface. The specified degree of cleanliness and accuracy of the surface shape are achieved by grinding and subsequent polishing, which basically constitute the essence of the process of mechanical processing of optical elements. Based on the literature data [1], it is known that a K2Cr2O7 (100 mg) / H2SO4 (10 ml) / H2O (40 ml) solution is a typical and good etchant for semiconductors, including zinc sulfide, which provides a mirror surface without defects caused by grinding and polishing. It is known that the Cr2O72- ion has a lower degree of hydration compared to the CrO42-, and in [1] the main complexing reagent for A2B6 semiconductors is sulfuric acid. Due to the above mentioned, we decided to study in this work of the etching process of zinc sulfide in a solution of the composition K2CrO4 (100 mg) / H2SO4 (10 ml) / H2O (40 ml) and in K2Cr2O7 (100 mg) / H2SO4 (10 ml) / H2O (40 ml) in the temperature range 20-90 °C. Kinetic regularities were obtained, on the basic of which assumptions were made about the mechanisms of interaction of zinc sulfide with a solution of a given composition. Based on the results of the qualitative analysis, the schemes of the ongoing chemical reactions have been established. A chemical-mechanical treatment was carried out based on H2SO4 with the addition of K2CrO4 and K2Cr2O7 as an oxidizing agent in order to study their effect on the polishing rate and the quality of optical elements made of zinc sulfide. The samples were polished using an aqueous solution of synthetic diamond micropowder with a grain size of 2 µm and 1 µm. The geometry of the surface was studied using a “KUGLER KU-6” interferometer and an “Axioplan 2” microscope. Based on the distribution functions of defects (scratches and dots) on the surfaces [2], it was found that a better surface quality in the CMP	chemical etching, chemical-mechanical polishing (CMP), zinc sulfide, surface quality