MgB2 Superconducting Films Fabricated on Copper Substrate by Hybrid Physical-Chemical Vapor Deposition

2007 ◽  
Vol 546-549 ◽  
pp. 1919-1922
Author(s):  
Fen Li ◽  
Tao Guo ◽  
Kai Cheng Zhang ◽  
Chin Ping Chen ◽  
Qing Rong Feng

The thick MgB2 films have been successfully grown on the Cu substrate by the technique of hybrid physical-chemical vapor deposition (HPCVD). The films are about 2 ~ 3 μm and quite dense. They possess the Tc (onset), as high as 37-38 K, and sharp transition ~ 0.8 K. X-ray diffraction (XRD) indicates their polycrystalline character. The upper critical field at T=0K, HC2(0), is extrapolated as 15.3T. The controlled growth of MgB2 film on Cu substrate opens a new route in the preparation of MgB2 tape materials.

1995 ◽  
Vol 406 ◽  
Author(s):  
M. S. Gaffneyt ◽  
C. M. Reavesl ◽  
A. L Holmes ◽  
R. S. Smith ◽  
S. P. DenBaars

AbstractMetalorganic chemical vapor deposition (MOCVD) is a process used to manufacture electronic and optoelectronic devices that has traditionally lacked real-time growth monitoring and control. We have developed control strategies that incorporate monitors as real-time control sensors to improve MOCVD growth. An analog control system with an ultrasonic concentration monitor was used to reject bubbler concentration disturbances which exist under normal operation, during the growth of a four-period GaInAs/InP superlattice. Using X-ray diffraction, it was determined that the normally occurring concentration variations led to a wider GaInAs peak in the uncompensated growths as compared to the compensated growths, indicating that closed loop control improved GaInAs composition regulation. In further analysis of the X-ray diffraction curves, superlattice peaks were used as a measure of high crystalline quality. The compensated curve clearly displayed eight orders of satellite peaks, whereas the uncompensated curve shows little evidence of satellite peaks.


1991 ◽  
Vol 243 ◽  
Author(s):  
A. Greenwald ◽  
M. Horenstein ◽  
M. Ruane ◽  
W. Clouser ◽  
J. Foresi

AbstractSpire Corporation has deposited strontium-barium-niobate by chemical vapor deposition at atmospheric pressure using Ba(TMHD), Sr(TMHD), and Nb ethoxide. Deposition temperature as 550°C in an isothermal furnace. Films were deposited upon silicon (precoated with silica), platinum, sapphire, and quartz. Materials were characterized by RBS, X-ray diffraction, EDS, electron, and optical microscopy. Electrical and optical properties were measured at Boston University.


2005 ◽  
Vol 862 ◽  
Author(s):  
Kanji Yasui ◽  
Jyunpei Eto ◽  
Yuzuru Narita ◽  
Masasuke Takata ◽  
Tadashi Akahane

AbstractThe crystal growth of SiC films on (100) Si and thermally oxidized Si (SiO2/Si) substrates by hot-mesh chemical vapor deposition (HMCVD) using monomethylsilane as a source gas was investigated. A mesh structure of hot tungsten (W) wire was used as a catalyzer. At substrate temperatures above 750°C and at a mesh temperature of 1600°C, 3C-SiC crystal was epitaxially grown on (100) Si substrates. From the X-ray rocking curve spectra of the (311) peak, SiC was also epitaxially grown in the substrate plane. On the basis of the X-ray diffraction (XRD) measurements, on the other hand, the growth of (100)-oriented 3C-SiC films on SiO2/Si substrates was determined to be achieved at substrate temperatures of 750-800°C, while polycrystalline SiC films, at substrate temperatures above 850°C. From the dependence of growth rate on substrate temperature and W-mesh temperature, the growth mechanism of SiC crystal by HMCVD was discussed.


2000 ◽  
Vol 288 (2) ◽  
pp. 217-222 ◽  
Author(s):  
O Durand ◽  
R Bisaro ◽  
C.J Brierley ◽  
P Galtier ◽  
G.R Kennedy ◽  
...  

2003 ◽  
Vol 764 ◽  
Author(s):  
R. Nagarajan ◽  
J.H. Edgar ◽  
J. Pomeroy ◽  
M. Kuball ◽  
T. Aselage

AbstractThe chemical vapor deposition of icosahedral boron arsenide, B12As2, on 6H-SiC (0001) (on and off-axis) substrates was studied using hydrides as the reactants. The effects of temperature and reactant flow rates on the phases deposited and the crystal quality were determined. The growth rate increased with temperature from 1.5μm/h at 1100°C to 5 μm/h at 1400°C and decreased thereafter. X-ray diffraction revealed that the deposits were amorphous when the deposition temperature is below 1150° C. Above 1150°C, smooth B12As2 films were formed on 6H-SiC substrates with an orientation of (0001) B12As2 parallel to 6H-SiC (0001). Raman spectroscopy confirmed the strongly c-axis oriented nature of B12As2 film on 6H-SiC.


1985 ◽  
Vol 132 (2) ◽  
pp. 482-488 ◽  
Author(s):  
Minoru Nakamura ◽  
Yasuhiro Mochizuki ◽  
Katsuhisa Usami ◽  
Yoshiko Itoh ◽  
Tadashi Nozaki

2014 ◽  
Vol 608 ◽  
pp. 127-131 ◽  
Author(s):  
Suttinart Noothongkaew ◽  
Supakorn Pukird ◽  
Worasak Sukkabot ◽  
Ki Seok An

ZnO nanowalls were synthesized by chemical vapor deposition at temperature of 650 °C for 1 hour on the silicon substrate. The morphologies of samples were characterized by scanning electron microscopy (SEM). The result from X-ray diffraction (XRD) confirmed that the ZnO nanowalls were vertical c-axis orientation. A room temperature Photoluminescence peak at 378 nm is ultraviolet emission (UV) and the broad peak at wavelengths around 450-650 nm is corresponding to the green emission of ZnO nanostructure. This synthesis may be applicable for gas sensor or solar cells.


2007 ◽  
Vol 539-543 ◽  
pp. 1230-1235 ◽  
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim

We have synthesized the high-density Ga2O3 nanowires on gold (Au)-coated silicon substrates using metalorganic chemical vapor deposition. The nanowires exhibited one-dimensional structures having circular cross sections with diameters in the range of 30-200 nm. The energy dispersive x-ray spectroscopy revealed that the nanowires contained elements of Ga and O, without Au-related impurities. X-ray diffraction analysis and high-resolution transmission electron microscopy showed that the Ga2O3 nanowires were crystalline.


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