Nucleation And Growth of Yttria-Stabilized Zirconia Thin Films Using Combustion Chemical Vapor Deposition

2002 ◽  
Vol 756 ◽  
Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Sergey Yarmolenko ◽  
Qiuming Wei

ABSTRACTLiquid fuel combustion chemical vapor deposition technique was successfully used for YSZ thin film processing. The nucleation rates were obtained for the samples processed at different temperatures and total-metal-concentrations in the liquid fuel. An optimum substrate temperature was found for the highest nucleation rate. The nucleation rate was increased with the total-metal-concentration. Structural evolution of the thin film in the early processing stage was studied with regard to the formation of nuclei, crystallites and final crystals on the films. The films were found to be affected by high temperature annealing. The crystals and the thin films were characterized with scanning electron microscopy.

2005 ◽  
Vol 862 ◽  
Author(s):  
A. R. Middya ◽  
J-J. Liang ◽  
K. Ghosh

AbstractIn this work, we report on next-generation hot wire chemical vapor deposition technique, we call it ceramics hot-wire CVD. Using a new concept of rectangular ceramics filament holder and “confinement of thermal radiation from the filament”, a “new form” of polycrystalline silicon thin films has been developed at low temperature (˜ 250°C). The grains are found to be symmetrically distributed in array along the parallel lines, in (111) direction. On the surface of individual grains, “five-fold” and “six-fold” symmetries have been observed and we suspect that we developed “buckyball” type “giant silicon molecular solids” with different crystalline silicon lattice other than standard single-crystal silicon structure. We observed rarely found “icosaderal” symmetry in silicon thin films. This hypothesis has been supported by multiple Raman active transverse optical modes and the crystallographic structure analyzed by X-ray diffraction.


Author(s):  
Zhigang Xu ◽  
Jag Sankar ◽  
Qiuming Wei ◽  
Jim Lua ◽  
Sergey Yamolenko ◽  
...  

Thin film of YSZ electrolyte is highly desired to reduce the electrical resistance in SOFCs. YSZ thin Films have been successfully produced using liquid fuel combustion chemical vapor deposition (CCVD) technique. Nucleation of the YSZ particles were investigated based on two processing parameters, i.e., substrate temperature and total-metal-concentration in the liquid fuel. An optimum substrate temperature was found for highest the nucleation density. The nucleation density was increased with the total-metal-concentration. Microstructure evolution of the YSZ particles in the early stage in film growth was also studied. It was found that the particle growth rate was linear with processing time, and the particle orientation was varying with the time in the early stage of the film processing. To enhance the film growth rate, the effect of thermophoresis was studied. By increase the temperature gradient towards substrate, the effect of thermophoresis was enhanced and the film growth is also increased.


Author(s):  
T. W. Scharf ◽  
S. V. Prasad ◽  
M. T. Dugger ◽  
T. M. Mayer

Tungsten disulphide (WS2) and molybdenum disulfide (MoS2), which belong to the family of transition metal dichalcogenides, are well known for their solid lubricating behavior. Thin films of MoS2 and WS2 exhibit extremely low coefficient of friction (COF ∼0.02 to 0.05) in dry environments, and are typically applied by sputter deposition, pulsed laser ablation, evaporation or chemical vapor deposition, which are essentially either line-of-sight or high temperature processes. With these techniques it is difficult to coat surfaces shadowed from the target, or uniformly coat sidewalls of three-dimensional or high aspect ratio structures. For applications such as micromechanical (MEMS) devices, where dimensions and separation tolerances are small, and aspect ratios are large, these traditional deposition techniques are inadequate. Atomic layer deposition (ALD) is a chemical vapor deposition technique that could overcome many of these problems by using sequential introduction of gaseous precursors and selective surface chemistry to achieve controlled growth at lower temperatures, but the chemistry needed to grow transition metal dichalcogenide films by ALD is not known.


1989 ◽  
Vol 169 ◽  
Author(s):  
Shinji Gohda ◽  
Yasuhiro Maeda

AbstractBi‐Sr‐Ca‐Cu‐0 superconducting thin films have been prepared on MgO substrates by a Metalorganic Chemical Vapor Deposition technique using an infrared lamp. It was found in this study that the film composition ratio could be precisely controlled by using this technique. A zero resistance at 81K was obtained for Bi1Sr1.3Ca0.9Cu1.8Ox film grown at 850°C. The critical current density of this film was 1.0xl03A/cm2 at 77K.


Sign in / Sign up

Export Citation Format

Share Document