Improvement of preferred orientation of NiAl/CrMn underlayers deposited on prebaked tape substrates
It was observed that the coercivity of CoCrPt films deposited on a polyimide tape was much lower than the coercivity deposited on a rigid glass substrate under identical conditions. X-ray diffraction showed that the desirable (112) and (110) texture of the NiAl/CrMn underlayers on the tape substrate was severely degraded during the deposition process. This resulted in the destruction of (10.0) growth texture of CoCrPt films and a significant reduction of magnetic coercivity. However, degassing of the tape substrate under vacuum before deposition significantly enhanced the magnetic properties. The coercivity of the film reached 170 kA/m which is near that achieved on a glass substrate. Auger analysis also revealed that oxygen was present in the NiAl/CrMn underlayers deposited without degassing the tape substrate.
Effects of impurity gases on properties of Co-Cr perpendicular recording media in high-rate and continuous sputtering process
In a roll coater system based on dc-magnetron sputtering, the influence of impurity gas was studied in terms of magnetic properties of the Co-Cr perpendicular recording media. It was found that only water came out from the organic base film during sputtering. This deteriorates significantly the perpendicular anisotropy of the Co-Cr medium. To eliminate the influence of water, the base film needed to be degassed by heating the film before sputtering. Intentional addition of nitrogen, oxygen and hydrogen was examined to understand their individual effects. Although nitrogen is less reactive with the Co-Cr film than oxygen, a very small amount of nitrogen causes more severe degradation of the perpendicular anisotropy than oxygen does. On the other hand, hydrogen does not react with any film, Co-Cr nor Cu-Mo Permalloy, but its addition influences the coercive force of both films without any change of anisotropy nor crystal orientation.
Modeling of chemical reactors—XXIX mixing-cell model for packed bed reactors. Steady state considerations. Problems of multiplicity
Abstract The axial heat and mass transfer in tubular catalytic reactors may be described by mixing-cell model and diffusion model as well. The diffusion description yields for a strong exothermic reaction and adiabatic conditions three steady state profiles, on the other hand the mixing-cell model gives rise to more than three steady states. A simple numerical and graphical analysis for mixing-cell model is presented.