Deposition of Superconducting Tl-Ba-Ca-Cu-O Phases on Metal Foils by Metal-Organic Chemical Vapor Deposition

1992 ◽  
Vol 275 ◽  
Author(s):  
D. L. Schulzi ◽  
B. Hano ◽  
D. Neumayer ◽  
B. J. Hinds ◽  
T. J. Markst ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Foils ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTThe synthesis of superconducting Tl-Ba-Ca-Cu-O thin films on metal foils (Au and Ag) by metal-organic chemical vapor deposition (MOCVD) has been investigated. Ba-Ca-Cu-O-(F) films are first prepared via MOCVD using fluorinated “second generation” metal-organic precursors. After an intermediate anneal with water vapor-saturated oxygen to promote removal of F, Tl is introduced by annealing in the presence of a mixture of oxides (Tl2O3, BaO, CaO, CuO) of a specific composition. Characterization of the thin films by scanning electron microscopy, EDX, x-ray diffraction, and variable temperature magnetization measurements has been carried out. High temperature superconductor (HTS) films of Tl2Ba2Ca1Cu2O8−x on Au foil exhibit a magnetically derived Tc = 80K and a high degree of texturing with the crystallite c-axes oriented perpendicular to the substrate surface as evidenced by enhanced (000 x-ray diffraction reflections. Thin film coverage on Ag foil becomes non-contiguous during the (Tl2O3, BaO, CaO, CuO) mixture anneal.

Metal-Organic Chemical Vapor Deposition of Epitaxial Tl2Ba2Ca2Cu3O10−x Thin Films

1993 ◽  
Vol 335 ◽  
Author(s):  
Bruce J. Hinds ◽  
Jon L. Schindler ◽  
Bin Han ◽  
Deborah A. Neumayer ◽  
Donald C. Degroot ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Superconducting Thin Films ◽  
X Ray ◽  
Partial Pressures ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractSuperconducting thin films of Tl2Ba2Ca2Cu3O10−x (TL-2223) have been grown on single crystal (110) LaAlO3 using a two-step process. Ba2Ca2Cu3Ox precursor films are deposited via metal-organic chemical vapor deposition (MOCVD) in a horizontal hot walled reactor. The second generation precursors Ba(hfa)2•tet, Ca(hfa)2•tet, and Cu(hfa)2 (hfa = hexafluoroacetylacetonate, tet = tetraglyme) were used as volatile metal sources due to their superior volatility and stability. Tl was introduced into the film via a high temperature post anneal in the presence of a Tl2O3:BaO:CaO:CuO pellet (1:2:2:3 ratio). Low O2 partial pressures were used to reduce the temperature in which the TI-2223 phase forms and to improve the surface morphology associated with a liquid phase intermediate. Films are highly oriented with the c-axis perpendicular to the substrate and a-b axis epitaxy is seen from x-ray φ- scans. The best films have a resistively measured Tc of 115K and a magnetically derived Jc of 6×105 A/cm2 (77K, 0 T). Preliminary surface resistance measurements, using parallel plate techniques, give Rs = 0.35 mΩ at 5K (ω = 10 GHz).

The Growth and Optimization of InPSb/InGaAs/InAsSb Strained-Layer Superlattice Emitters by Metal Organic Chemical Vapor Deposition

1995 ◽  
Vol 379 ◽  
Author(s):  
R. M. Biefeld ◽  
S. R. Kurtz
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strained Layer ◽  
Metal Organic ◽  
Interface Layers ◽  
Organic Chemical Vapor Deposition

ABSTRACTWe have prepared InAsSb/InGaAs strained-layer superlattices (SLS's) and InPSb confinement layers using metal-organic chemical vapor deposition (MOCVD) for use as infrared emitters. X-ray diffraction was used to determine lattice matching as well as composition and structure of the SLS's. Photoluminescence linewidth and intensity were used as a measure of the quality of the structures. Typical FWHM were less than 10 meV. The presence of interface layers were indicated by broadened x-ray diffraction peaks for samples grown under non-optimized conditions. Two types of interfacial layers apparently due to a difference in composition at the interfaces were observed with transmission electron microscopy (TEM). The width of the x-ray peaks can be explained by a variation of the interfacial layer thicknesses. Optimized growth resulted in SLS's with narrow x-ray peaks and high radiative efficiency. Room temperature LEDs operating between 4-5 μm have been prepared.

Transparent conducting indium oxide thin films grown by low-temperature metal organic chemical vapor deposition

2007 ◽  
Vol 515 (5) ◽  
pp. 2921-2925 ◽  
Author(s):  
Chunyu Wang ◽  
Volker Cimalla ◽  
Genady Cherkashinin ◽  
Henry Romanus ◽  
Majdeddin Ali ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Indium Oxide ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Transparent Conducting ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Study on ZrO2:Er Thin Films Fabricated by Metal-Organic Chemical Vapor Deposition

2003 ◽  
Vol 42 (Part 1, No. 5A) ◽  
pp. 2839-2842 ◽  
Author(s):  
Jeong Hoon Park ◽  
Kug Sun Hong ◽  
Woon Jo Cho ◽  
Jang-Hoon Chung
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

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.

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