The Deposition, Fabrication and Characteristics of High Critical Temperature Devices

1987 ◽  
Vol 99 ◽  
Author(s):  
G. W. Morris ◽  
M. G. Blamire ◽  
R. E. Somekh ◽  
E. J. Tomlinson ◽  
J. E. Evetts
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Critical Temperature ◽  
Heat Treatments ◽  
Sputter Deposition ◽  
High Critical Temperature ◽  
The Third ◽  
Current Voltage ◽  
Device Structures ◽  
Temperature Heat

ABSTRACTIn the first section of this paper the sputter deposition of thin films of YBa2Cu3O7−x is considered. In the second section low and high temperature heat treatments are discussed in the light of the thermodynamics of the material and in the third the development, fabrication and current-voltage (IV) characteristics of a variety of device structures are described, including the hysterctic characteristics of certain YBa2Cu3O7−x / YBa2Cu3O7−x devices that reveal Josephson supcrcurrcnt tunnelling.

Fabrication and electrical properties of polymer-derived ceramic (PDC) thin films for high-temperature heat flux sensors

2011 ◽  
Vol 165 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Duckbong Seo ◽  
Sunghoon Jung ◽  
Stephen J. Lombardo ◽  
Z.C. Feng ◽  
J.K. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Heat Flux ◽  
High Temperature ◽  
Electrical Properties ◽  
Heat Flux Sensors ◽  
Polymer Derived Ceramic ◽  
Temperature Heat

Application of ZnO to Passivate the GaN-based Device Structures

2007 ◽  
Vol 1035 ◽  
Author(s):  
Eliana Kaminska ◽  
Anna Piotrowska ◽  
Marie-Antoinette di Forte Poisson ◽  
Sylvain Delage ◽  
Hacene Lahreche ◽  
...  
Keyword(s):  
Thin Films ◽  
Sputter Deposition ◽  
High Resistivity ◽  
Leakage Currents ◽  
Gan Hemt ◽  
Reactive Sputter Deposition ◽  
Device Structures ◽  
Hygroscopic Nature ◽  
Output Characteristics ◽  
Lattice Matched

AbstractThe fabrication of high-resistivity ZnO-based thin films lattice-matched to AlGaN/GaN structures has been developed. It relies on low-temperature reactive sputter deposition of ZnO:Sb from ZnSb target. Taking into account the hygroscopic nature of ZnO surface, an additional coating by Si3N4 films is applied to ensure the humidity protecition. The developped passivation suppresses leakage currents in Schottky diods, and substantially improves output characteristics of AlGaN/GaN HEMT.

scholarly journals Computer Simulation of Scattered Ion and Sputtered Species Effects in Ion Beam Sputter-Deposition of High Temperature Superconducting Thin Films

1992 ◽  
Vol 268 ◽  
Author(s):  
Alan R. Krauss ◽  
Orlando Auclello
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Ion Beam ◽  
Sputter Deposition ◽  
Primary Beam ◽  
Angle Of Incidence ◽  
Ion Beam Sputtering ◽  
High Temperature Superconducting ◽  
Target Composition ◽  
Ion Beam Sputter Deposition

ABSTRACTIon beam sputter-deposition is a technique currently used by many groups to produce single and multicomponent thin films. This technique provides several advantages over other deposition methods, which include the capability for yielding higher film density, accurate stoichiometry control, and smooth surfaces. However, the relatively high kinetic energies associated with ion beam sputtering may lead to difficulties if the process is not properly controlled. Computer simulations have been performed to determine net deposition rates, as well as the secondary erosion, lattice damage, and gas implantation in the films, associated with primary ions scattered from elemental Y, Ba and Cu targets used to produce high temperature superconducting Y-Ba-Cu-O films. The simulations were performed using the TRIM code for different ion masses and kinetic energies, and different deposition geometries. Results are presented for primary beams of Ar+, Kr+ and Xe+ incident on Ba and Cu targets at 0° and 45° with respect to the surface normal, with the substrate positioned at 0° and 45°. The calculations indicate that the target composition, mass and kinetic energy of the primary beam, angle of incidence on the target, and position and orientation of the substrate affect the film damage and trapped primary beam gas by up to 5 orders of magnitude.

MAGNETISM, PHONONS AND ANISOTROPY OF HIGH TEMPERATURE CUPRATES SUPERCONDUCTORS

2001 ◽  
Vol 15 (05) ◽  
pp. 511-526 ◽  
Author(s):  
JACQUES FRIEDEL ◽  
MAHITO KOHMOTO
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Fermi Level ◽  
Density Of States ◽  
Hole Doping ◽  
Magnetic Fluctuations ◽  
Phonon Coupling ◽  
High Critical Temperature ◽  
Bloch Functions ◽  
Gap Anisotropy

Phonon or electron mediated weak BCS attraction is enough to have high critical temperature if a van Hove anomaly is at work. This could apply to electron doped compounds and also to compounds with CuO 2 planes overdoped in holes, where T c decreases with increasing doping. If phonons dominate, it should lead to an anisotropic but mainly s superconductive gap, as observed recently in overdoped LaSrCuO, and probably also in electron doped compounds. If electrons dominate, a d-gap should develop as observed in a number of cases. In the underdoped range, the observed decrease of T c with hole doping can be related in all cases to the development of antiferromagnetic fluctuations which produces a magnetic pseudogap, thus lowering the density of states at the Fermi level. The observed mainly d-superconductive gap then can be due to a prevalent superconductive coupling through antiferromagnetic fluctuations; it could also possibly be attributed to the same phonon coupling as in the overdoped range, now acting on Bloch functions scattered in the magnetic pseudogap. More systematic studies of superconductive gap anisotropy and of magnetic fluctuations would be in order.

POSSIBLE OBSERVATION OF TUNNELING CURRENTS IN NdBaCuO SUPERCONDUCTING THIN FILMS

2003 ◽  
Vol 17 (04n06) ◽  
pp. 905-909
Author(s):  
A. NIGRO ◽  
P. ROMANO ◽  
B. SAVO
Keyword(s):  
Thin Films ◽  
Critical Temperature ◽  
Tunneling Current ◽  
Superconducting Thin Films ◽  
Quasiparticle Tunneling ◽  
Current Voltage ◽  
Oriented Films ◽  
Normal Resistance ◽  
Current Voltage Characteristics ◽  
Tunneling Behavior

Phenomena resembling a tunneling behavior have been observed on dc sputtered Nd1+xBa2-xu3Oy c-axis oriented films. The current voltage characteristics at 4.2K give evidence of quasiparticle tunneling current as usually measured in superconductor-insulator-normal metal or superconductor-insulator-superconductor junctions, with normal resistance values of about 10Ω. In the conductance curves, peak at about +/-16mV are clearly visible. An analysis of these features is presented up to temperatures close to the sample critical temperature.

Mo-W Interdiffusion and the Influence on Potassium Bubbles in W Lamp Wire

1996 ◽  
Vol 458 ◽  
Author(s):  
B. P. Bewlay ◽  
C. L. Briant ◽  
M. L. Murray
Keyword(s):  
High Temperature ◽  
Tungsten Wire ◽  
Heat Treatments ◽  
Diffusion Couples ◽  
Microstructural Changes ◽  
Heat Treated ◽  
Temperature Heat ◽  
Microprobe Data ◽  
Equiaxed Grains

ABSTRACTThe effects of Mo contamination on the microstructure of lamp-grade tungsten wire are investigated in this study. Mo is often used as the mandrel material in the coiling of lamp filaments, and when utilized during high temperature heat treatments significant amounts of Mo can diffuse into the W. In this study, W-Mo diffusion couples were prepared and heat treated at temperatures of 2500°C and above to intentionally contaminate the W with Mo. After dissolution of the Mo and additional high temperature heat treatments of the W, equiaxed grains were observed in the W and excessive porosity was also observed. Explanations for these microstructural changes are discussed. Microprobe data were also obtained to quantify interdiffusion between the W and Mo.

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