EXCIMER LASER INDUCED MODIFICATION OF CERAMICS SURFACE

本项目的目的是利用准分子激光注入对陶瓷进行表面改性。通过这种技术，可以在介电材料上制造导电薄层和/或特殊涂层薄膜。本实验使用的陶瓷为石英（SiO_2）、氧化铝（Al_2O_3）和人牙釉质羟基磷灰石(Ca_<10>(PO_4)_6(OH)_2)。Au原子被植入到氧化物中，Ag和F原子被植入到牙釉质中。植入部位的深度分布采用Ratherford后向散射光谱（RBS）分析，平面分布采用x射线显微分析（XMA）分析。本工程获得的主要特征如下：1。用准分子激光（< λ >=248nm,< τ >=23ns）照射Au原子在陶瓷表面气相沉积后的SiO_2和al_2o_3。(1)随着辐照能量密度的增加，注入Au原子的数量减少。在0.5 J/cm^2左右获得了最大值。(2) SiO_2在[0.5 J/cm^2]下最大深度为350nm， Al_2O_3在[0.2 J/cm^2]下最大深度为650nm。(3)比值Ns/Nb是能量密度的函数，其中Ns和Nb分别是近表面和块体中Au原子的数量。(4)上述实验结果与红外和可见光激光的实验结果完全不同。在这种情况下，CO_2激光（< λ >=10.6<micrn>m,<tau>=0.5s）照射氟化（Ag(NH_3)_2F）珐琅表面。(1)注入F原子的最大深度为20 J/cm^2，约为1.2<micrn>m。这个最大深度大约是未辐照牙釉质的1.7倍。(2)采用激光辐照法从牙釉质表面溅射出部分银原子。

The aim of the present project is a surface modification of ceramics by excimer laser implantation. By this technique, it is possible to make a conductive thin layer and/or a special coating film on dielectric materials. The ceramics used in this experiment are quartz (SiO_2), alumina (Al_2O_3) and human dental enamel as hydroxyapatite (Ca_<10>(PO_4)_6(OH)_2). Au atoms were implanted into the oxides and Ag and F atoms were implanted into the enamel. The analysis for implanted part was done by Ratherford backscattering spectroscopy (RBS) for the depth distribution and X-ray micro analysis XMA for the plane distribution.The main features obtained in this project are as follows.1. SiO_2 and Al_2O_3These oxides were irradiated by excimer laser (<lambda>=248nm ,<tau>=23ns ) after vopour deposition of Au atoms on ceramics surface.(1)The amount of implanted Au atoms decreases with increasing irradiation energy density. Maximum amount was obtained at around 0.5 J/cm^2.(2)Maximum depth was 350nm for SiO_2 at [0.5 J/cm^2 and 650nm for Al_2O_3 at [0.2 J/cm^2.(3)The ratio ,Ns/Nb is a function of energy density where Ns and Nb are the amount of Au atoms near surface and in the bulk , respectively.(4)Above experimental results are completely different from that obtained by useing with IR- and visible-laser light.2. Ca_<10>(PO_4)_6(OH)_2In this case , CO_2 laser(<lambda>=10.6<micrn>m ,<tau>=0.5s ) irradiation was done fluoride (Ag(NH_3)_2F)- coated enamel surface.(1)Maximum depth of implanted F atoms was observed at 20 J/cm^2 and was about 1.2<micrn>m. This maximum depth is about 1.7 times larger than the case of an unirradiated enamel.(2)Part of Ag atoms was sputtered from enamel surface by laser irradiation.