Lauri Aarik will defend his doctoral thesis titled “Atomic layer deposition and characterization of thin oxide films for application in protective coatings” on 5. Detsember 2017 at 14:15 at W. Ostwaldi 1, room B103.
Prof. Väino Sammelselg, Institute of Physics University of Tartu
Prof. Mato Knez, CIC nanoGUNE/Ikerbasque, Spain
Dr. Ilona Oja Acik, Tallinn University of Technology
Prolonging the lifetime and reducing the amount and cost of materials, used in different kind of products, are two big problems that have to be solved to decrease the ecological footprint of contemporary society. Corrosion is a process, which takes place in almost all environments and reduces the durability of materials, and sometimes makes impossible application of cheap and easily accessible materials. One of the possibilities to protect materials against corrosion is to add a barrier layer of a durable material on the top of a product to isolate it from environment and thereby increases its lifetime or make possible its application in more aggressive environments. However, due to increasing requirements on precision and construction complexity of high-technology production, novel high-precision techniques are needed also for preparation of appropriate protective coatings. Therefore, need for corresponding studies is growing day by day. In this study, application of the atomic layer deposition method for deposition of thin precisely controlled protective coatings was investigated. During the studies novel atomic layer deposition equipment, which made possible deposition of protective coatings onto the inner surface of hermetic containers, was constructed and tested. Secondly, to advance the preparation methods and improve the properties of the protective coatings, atomic layer deposition processes based on new precursor combinations, TiCl4-O3 for deposition of TiO2 and AlCl3-O3 for deposition of Al2O, were developed and physical as well as chemical properties of coatings obtained in these processes were investigated. In the experiments, the potential of these coatings to protect surface of stainless steel was demonstrated.