Structure of rhenium coatings obtained by CVD

Abstract

By chemical vapor deposition in the hydrogen atmosphere from Re2(CO)10 and Re(CO)3(Cp) on steel and ceramic (C/SiC) substrates, rhenium coatings are obtained with an average thickness of 3–13 μm, when Re2(CO)10 is used, and of 2–8 μm when depositing from Re(CO)3(Cp). The coatings are studied by X-ray diffraction and scanning electron microscopy. It is shown that when Re2(CO)10 is used, an increase in the deposition temperature results in the growth of textured coatings with preferred orientation of crystallites in the [0 0 2] direction. At the same time, a tendency for decreasing the size of rhenium crystallites is observed. With the change of evaporator temperature, the structure of Re coatings obtained from Re(CO)3(Cp) on steel substrates changes considerably: from compact non-layered without the obvious growth direction (T evaporator = 120°C) to a three-layer structure, where the initial layer has a compact structure followed by columnar and powdered layers (T evaporator = 110°C). A fine compact coating is formed on ceramic substrates at an evaporator temperature of 110°C.