Author: Jahanfar Hanieh ; Type of thesis: Master Thesis
Abstract:
The economic damages in the world because of corrosion are considered as one of the problems in economic developments . The global economic damages of corrosion is in the scale of billion dollars . Just in the US in one year the total economic damage because of corrosion is around a half of billion dollars ! .
As much as corrosion is dangerous and considerable, protection against corrosion is important which is seriously followed by researchers .
The word protective usually refers to the corrosion . The corrosion of metals typically takes place in the reinforced concrete. It happens when there is an anode where oxidation occurs, and a cathode where reduction occurs.
Considering the importance of protection against corrosion , my thesis project was started with one of the best methods of protection which is thin film deposition and with one of the most interesting protective material which is CeO2 .
Also its necessary to mention that another projects have been done in the superconductive laboratory of INFN in Legnaro with the object of deposition of CeO2 thin film as a protector but in the last project the used target has been CeO2 target and just a certain sputtering technique has been used so we decided to compare different sputtering techniques which was possible through using different power supplies and comparing them, with a more industrial target .This is why we chose Ce target and 4 different kinds of power supplies as DC, AC ,RF and Pulsed DC to be compared through using the main system which was reactive magnetron sputtering . By using the mentioned 4 power supplies and comparing them the most important parameters have been deposition rate and film stoichiometry as sensitive functions of reactive gas partial pressure .
Meanwhile as one of the examples of corrosion is oxidation of the copper coins we chose protection of coins as the main application for my thesis. Circulating mintage of copper coins (Like 1 , 2 or 5 cents) just in Italy have been around 400 million coins in 2009 . If we multiply this circulation to the cost of mintage new coins to be replaced with old ones which are usually effected by corrosion we can estimate a big economic damage in Italy because of corrosion So we decided to specifically apply our protection method to the Euro copper coins as a reasonable application.