Study On Properties Of Cr-O Films Deposited By Pulsed Bias Arc Ion Plating

Chrome oxide with high hardness, high temperature stability, excellent corrosion resistance and other properties can be applied to metallurgy, pigment, abrasive, fire-proof material and new development of melt-blown coatings, etc. In recent years, the study of chromium oxide films is mainly concentrated on the structure, mechanical properties, friction and wear properties, solar selective absorbing film and so on. In this paper chromic oxide films are synthesized on silicon and quartz glass by the pulsed bias arc ion plating. The structure, mechanical properties and optical properties of thin films is studied. It is looking forward to get good mechanical and optical properties of transparent film.Firstly, a series of uniform and transparent Cr-O films were synthesized on the silicon (111) and quartz glass substrates at different oxygen flow rates by pulsed bias arc ion plating. The results indicate that a series of transparent films are prepared. The thin films show good surface quality. The composition of the surface films remained invariant at different oxygen flow rates. The hardness of the films is all above 19.0 GPa, reaching the maximum value of 24.8 GPa when the oxygen flow rate is 160 sccm. The thin film show good transmittance and the maximum value is 71% when the oxygen flow rate is 80 sccm. The optical band gap reaches the maximum value of 1.81eV when the oxygen flow rate is 80 sccm.Secondly, a series of uniform and transparent Cr-0 films were synthesized onto the silicon (111) and quartz glass substrates at different bias voltages by pulsed bias arc ion plating. The results indicate that the bias voltage can improve the quality of the films significantly. Macroparticles and holes are observed on the surface of the films without application of bias voltage, while the films with bias voltage are uniform and smooth, the Cr2O3 phase appears and changes into CrO phase, while the bias voltage was applied and increased from-100 V to-500 V. With the increase of bias voltage, the hardness first increased and then decreased, reaching the maximum value of 24.4 GPa at the bias voltage of-300 V. The films show optical transmittance and the highest value is up to 72%. As the bias voltage rises, it is observed the first red shift and then blue shift of the absorption edge. The optical band gap reaches the maximum value of 1.88eV when the bias voltage is-200V.