Takafumi Okuma

High-performance MgO thin films for PDPs with a high-rate sputtering-deposition process

— A high-rate sputtering-deposition process for MgO thin films for PDP fabrication was recently developed. The deposition rate of the MgO thin film was about 300 nm/min which shows the possibility of production-line application. The MgO film deposited in this work has a higher density than that of other deposition processes such as electron-beam deposition and shows good discharge characteristics including firing voltage and discharge formation. These were achieved by controlling the stoichiometry and/or the impurity doping during the sputtering process.

Effects of the Driving Frequency on Temperature in a Multiphase AC Arc

Effects of the driving frequency on temperature in a multiphase ac arc were successfully clarified. A multiphase ac arc is one of the thermal plasmas, which is suitable for producing functional materials such as nanoparticles, in-flight glass melting, and waste treatment in terms of its large plasma volume, high-energy efficiency, and low flow velocity. The temperature and arc behavior in various driving frequencies were investigated by the observation system consisting of a high-speed video camera and bandpass filters for plasma spectroscopy. The temperature measurement was conducted on the basis of the Boltzmann plot method. The obtained results indicated that the arc behavior and its temperature field were strongly influenced by the driving frequency. An increase of the frequency led to concentrated arc region, higher arc temperature at the center of electrode region and lower arc fluctuation. The temperature and its distribution can be controlled depending on the material properties to be treated and the purpose of the process.