I am a TA for a vacuums course for sophomores pursuing an engineering physics degree. We are creating a deposition chamber utilizing a turbo and a bell jar for thermal evaporation. We were looking at depositing TiO2 onto a slide of some sort through thermal evaporation to examine it. We are very much in the brainstorming of this project and are struggling to know if our idea is plausible This course is informal and typically utilizes one-day experiments. I have not found much research of depositing TiO2, only Ti and was wondering if our idea is even possible?
Dear Delaney Boyle , thermal evaporation of TiO2 is really tricky, mainly due to its high melting ( 1843ºC) and more important boiling temperature (2972ºC), such temperatures are difficult to achieve even in conventional vacuum conditions used in thermal evaporation. Oxides in general have high boiling temperatures, so to lower the boiling temp you should use a extreme vacuum, which complicates design parameters (specially the vacuum pumps you need).
Even Ti is difficult to evaporate by thermal vacuum evaporation (at least with our machine), but it is still possible. We also wanted to deposit TiO2, so to achieve this we injected O2 through a gas port. In this way, oxidation of Ti happened during its flight from the crucible to the glass slide where we wanted to form the thin film of TiO2.
However, you can find abundant bibliography about the process or its variations, for instance, please have a look to the following papers:
Article Deposition at Low Substrate Temperatures of High-Quality TiO...
https://dl.uctm.edu/journal/node/j2013-6/2-Bedikyan_p-555-558.pdf
Hope it helps.
Are you planning to evaporate Ti metal. The melting point of Titanium is quite high 1668 degree Celsius. At such a high temperature in presence of oxygen rich environment, it will ideally deposit only TiO2. Melting point of TiO2 is still higher 1843 degree C.
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