Eu-doped Y2O3 phosphor films produced by electrostatic-assisted chemical vapor deposition

1999 ◽  
Vol 14 (7) ◽  
pp. 3111-3114 ◽  
Author(s):  
K. L. Choy ◽  
J. P. Feist ◽  
A. L. Heyes ◽  
B. Su
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Thermographic Phosphor ◽  
Ni Alloy ◽  
Phosphor Thermometry ◽  
Lifetime Decay ◽  
Deposited Films

Europium-doped yttrium oxide (Y2O3:Eu) thermographic phosphor films were deposited on Ni-alloy substrates using a novel and cost-effective electrostatic-assisted chemical vapor deposition (EACVD) technique. The thermoluminescence properties were studied under irradiation by an ultraviolet laser. It was found that crystallized Y2O3: Eu films could be deposited at a temperature as low as 550 °C. Annealing of the as-deposited films at higher temperatures (>1000 °C) improved the luminescence properties due to further crystallization processes. The correlation of the lifetime decay and temperature change of the films showed that the EACVD-deposited films are suitable for use in phosphor thermometry for high-temperature applications.

Vertically aligned growth of small-diameter single-walled carbon nanotubes on flexible stainless steels by alcohol catalytic chemical vapor deposition with Ir catalyst on alumina buffer layer

2021 ◽  
Author(s):  
Shu KONDO ◽  
Daiki YAMAMOTO ◽  
Kamal Prasad Prasad Sharma ◽  
Yazid Yaakob ◽  
Takahiro SAIDA ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Buffer Layer ◽  
Vapor Deposition ◽  
Small Diameter ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Chemical Vapor Deposition Growth ◽  
Catalytic Chemical Vapor Deposition ◽  
Single Walled Carbon ◽  
Vertically Aligned

Abstract We performed single-walled carbon nanotube (SWCNT) growth on flexible stainless-steel foils by applying alcohol catalytic chemical vapor deposition using an Ir catalyst with an alumina buffer layer. When the alumina thickness was 90 nm, vertically aligned SWCNTs with a thickness of 4.6 m were grown. In addition, Raman results showed that the diameters of most SWCNTs were distributed below 1.1 nm. Compared with conventional chemical vapor deposition growth where Si wafers are used as substrates, this method is more cost effective and easier to extend for mass production of small-diameter SWCNTs.

scholarly journals The Progress on Low-Cost, High-Quality, High-Temperature Superconducting Tapes Deposited by the Combustion Chemical Vapor Deposition Process

2001 ◽  
Vol 689 ◽  
Author(s):  
Shara S. Shoup ◽  
Marvis K. White ◽  
Steve L. Krebs ◽  
Natalie Darnell ◽  
Adam C. King ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Critical Current Density ◽  
Buffer Layer ◽  
Critical Current ◽  
Vapor Deposition ◽  
Low Cost ◽  
Chemical Vapor ◽  
High Critical Current Density ◽  
High Quality

ABSTRACTThe innovative Combustion Chemical Vapor Deposition (CCVD) process is a non-vacuum technique that is being investigated to enable next generation products in several application areas including high-temperature superconductors (HTS). In combination with the Rolling Assisted Biaxially Textured Substrate (RABiTS) technology, the CCVD process has significant promise to provide low-cost, high-quality lengths of YBCO coated conductor. The CCVD technology has been used to deposit both buffer layer coatings as well as YBCO superconducting layers. A buffer layer architecture of strontium titanate and ceria have been deposited by CCVD on textured nickel substrates and optimized to appropriate thicknesses and microstructures to provide templates for growing PLD YBCO with high critical current density values. The CCVD buffer layers have been scaled to meter plus lengths with good epitaxial uniformity along the length. A short sample cut from one of the lengths enabled high critical current density PLD YBCO. Films of CCVD YBCO superconductors have been grown on single crystal substrates with critical current densities over 1 MA/cm2. Work is currently in progress to combine both the buffer layer and superconductor technologies to produce high-quality coupons of HTS tape made entirely by the non-vacuum CCVD process.

Metal-organic chemical vapor deposition of ZrO2 films using Zr(thd)4 as precursors

1994 ◽  
Vol 9 (7) ◽  
pp. 1721-1727 ◽  
Author(s):  
Jie Si ◽  
Seshu B. Desu ◽  
Ching-Yi Tsai
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Organic Chemical ◽  
Deposition Rates ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Deposited Films

Synthesis of zirconium tetramethylheptanedione [Zr(thd)4] was optimized. Purity of Zr(thd)4 was confirmed by melting point determination, carbon, and hydrogen elemental analysis and proton nuclear magnetic resonance spectrometer (NMR). By using Zr(thd)4, excellent quality ZrO2 thin films were successfully deposited on single-crystal silicon wafers by metal-organic chemical vapor deposition (MOCVD) at reduced pressures. For substrate temperatures below 530 °C, the film deposition rates were very small (⋚1 nm/min). The film deposition rates were significantly affected by (i) source temperature, (ii) substrate temperature, and (iii) total pressure. As-deposited films are carbon free. Furthermore, only the tetragonal ZrO2 phase was identified in as-deposited films. The tetragonal phase transformed progressively into the monoclinic phase as the films were subjected to a high-temperature post-deposition annealing. The optical properties of the ZrO2 thin films as a function of wavelength, in the range of 200 nm to 2000 nm, were also reported. In addition, a simplified theoretical model which considers only a surface reaction was used to analyze the deposition of ZrO2 films. The model predicated the deposition rates well for various conditions in the hot wall reactor.

High temperature chemical vapor deposition of SiC

1996 ◽  
Vol 69 (10) ◽  
pp. 1456-1458 ◽  
Author(s):  
O. Kordina ◽  
C. Hallin ◽  
A. Ellison ◽  
A. S. Bakin ◽  
I. G. Ivanov ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Vapor Deposition ◽  
Chemical Vapor

Intelligent Process Control of Silicon Nitride Chemical Vapor Deposition

1994 ◽  
Vol 363 ◽  
Author(s):  
Paul S. Bowen ◽  
Steve K. Phelps ◽  
Harry I. Ringermacher ◽  
Richard D. Veltri
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Silicon Nitride ◽  
Process Control ◽  
Real Time ◽  
Vapor Deposition ◽  
Process Model ◽  
Chemical Vapor ◽  
Laser Ultrasonics ◽  
Hierarchical Architecture

AbstractThe chemical vapor deposition of silicon nitride can be used to protect advanced materials and composites from high temperature, corrosive, and oxidative environments. Desired coating characteristics, such as uniformity and morphology, cannot be measured in-situ by traditional sensors due to the adverse conditions within the high-temperature reactor. A control strategy has been developed which utilizes a process model and an advanced laser-based sensor to measure the deposition rate of the silicon nitride coating in real-time. The control system is based on a three level hierarchical architecture which functionally separates the process control into PID, supervisory and advanced sensor-based control. Optimal setpoint schedules for the supervisory level are derived from a quasi-fuzzy logic inverse mapping of the process model. An advanced sensor utilizing laser ultrasonics provides real-time coating thickness estimates. Model bias is characterized for each reactor and is correlated on-line with the sensor's deposit thickness estimate. Deviations from model predictions may result in parametric changes to the process model. New setpoint schedules are then created as input to the supervisory control level by regenerating the inverse map of the updated process model.

High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies

2016 ◽  
Vol 119 (14) ◽  
pp. 145702 ◽  
Author(s):  
Pramod Reddy ◽  
Shun Washiyama ◽  
Felix Kaess ◽  
M. Hayden Breckenridge ◽  
Luis H. Hernandez-Balderrama ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
High Temperature ◽  
Silicon Nitride ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Band Offsets ◽  
Pressure Chemical
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