Thermal Analysis and Control for Sputtering Deposition of High-Tc Superconducting Films

1992 ◽  
Vol 114 (1) ◽  
pp. 255-263 ◽  
Author(s):  
M. I. Flik ◽  
B. I. Choi ◽  
A. C. Anderson ◽  
A. C. Westerheim

For the preparation of high-quality films of high-Tc superconductors (HTSC) on crystalline substrates, it is necessary to control the substrate temperature accurately during deposition. This study shows that thermal radiation heat transfer in the deposition chamber governs the substrate temperature. The application of thin-film optics yields the emittance of the substrate holder-substrate-film composite as a function of the thickness of the growing film. In a single-target off-axis sputtering system, the substrate temperature is measured during film deposition using a novel method for the attachment of a thermocouple to the substrate front surface. For constant heater power, the measurements show a decrease of the substrate temperature, in agreement with the theoretical prediction. Based on the substrate emittance variation determined in this work, a pyrometric in-situ temperature measurement technique can be developed.

1991 ◽  
Vol 6 (7) ◽  
pp. 1595-1604 ◽  
Author(s):  
Kiyotaka Wasa ◽  
Hideaki Adachi ◽  
Kumiko Hirochi ◽  
Yo Ichikawa ◽  
Tomoaki Matsushima ◽  
...  

Basic thin film deposition processes for controlled deposition of the high-Tc superconductors of the Bi-systems are described. The layered structures of Bi-oxide superconductors are fabricated by a multitarget sputtering process. The multitarget sputtering process realizes the controlled deposition of single phase Bi-oxide superconductors, Bi2O2 · 2SrO · (n −1)CaO · nCuO2 for n = 1 to 5. The minimum thickness controlled by the multitarget sputtering is a half crystal unit-cell of around 15 Å, and the superlattices comprising (AkBk) · m, where A and B denote the Bi-oxide superconductors with different numbers of Cu–O layers, could be fabricated for k > 1, although ion mixing takes place during the sputtering deposition due to the bombardment of the highly energetic sputtered adatoms. Multitarget sputtering will be available for the fabrication of the artificially-made layered oxide superconductors (ALOS).


2012 ◽  
Vol 525-526 ◽  
pp. 9-12 ◽  
Author(s):  
Er Bao Liu ◽  
Xiu Fang Cui ◽  
Guo Jin ◽  
Qing Fen Li ◽  
Tian Min Shao

The niobium film is prepared by magnetron sputtering on the surface of the AZ91D magnesium alloy. The morphology, phase structure, roughness, nanohardness and elastic modulus of the niobium films were studied by filed emission scanning electron microscope, X-ray diffraction, atomic force microscope and nanoindentation respectively. The influences of film deposition parameters, such as substrate temperature, negative bias and power on the properties of films were investigated. The corrosion resistance of niobium films on magnesium alloy was investigated by electrochemical system. Results show that the microstructure, phase structure, roughness, nanohardness and elastic modulus of the niobium films are determined by power, negative bias and substrate temperature. And the corrosion resistance of magnesium alloy improved obviously when coated with the niobium films.


2002 ◽  
Vol 721 ◽  
Author(s):  
Bo Cheng ◽  
Kun Yang ◽  
B. L. Justus ◽  
W. J. Yeh

AbstractIn magnetic recording technology, barriers based on fundamental physical limits on the data density are being approached for the current longitudinal recording modes. However, demands for higher data storage density have escalated in recent years. Discrete perpendicular recording is a viable method to achieve 100 Gb per square inch and beyond. We report on the development of a novel technique to fabricate uniform arrays of nano-sized magnetic dots. Uniform arrays of nanometer-sized magnetic dots are obtained by magnetron sputtering deposition through a nanochannel glass replica mask. The platinum replica masks are fabricated using thin film deposition on etched nanochannel glass and contain uniform hexagonally patterned voids with diameters as small as 50 nanometers. The magnetic dot density can be as high as 1011 per square inch. Our method provides a simple yet effective way to create regularly arranged discrete magnetic media that can be used for perpendicular magnetic recording. The magnetic properties of the dots are studied with a vibrating sample magnetometer.


2020 ◽  
Vol 383 ◽  
pp. 125220 ◽  
Author(s):  
Adrien Chauvin ◽  
Lukas Horak ◽  
Elen Duverger-Nédellec ◽  
Milan Dopita ◽  
Pierre-Yves Tessier ◽  
...  

2019 ◽  
Vol 99 (4) ◽  
pp. 262-267 ◽  
Author(s):  
Shan-shan Bai ◽  
Dong Li ◽  
Liang Xu ◽  
Hui-chuan Duan ◽  
Jie Yuan ◽  
...  

Augmentation rhinoplasty is one of the most common plastic surgery procedures performed in Asia. Most Asian patients desire not only a natural-looking nose but also a nose with natural feel. Achieving such rhinoplasty outcomes with grafts has been a challenge for surgeons due to rigidity of grafting material. We propose a novel technique to address this limitation. A total of 200 healthy adult patients aged from 18 to 25 years were randomly chosen and classified into 5 groups: A, B, C, D, and control. Each group included 40 patients. The patients assigned to conventional grafting underwent rhinoplasty with L-shaped silicone prosthesis (group A) or expanded polytetrafluoroethylene (e-PTFE; group B), using traditional carving methods. The patients assigned to dynamic rhinoplasty underwent silicone (group C) or e-PTFE grafts (group D) using the modified double “V” method, which involves removing bilateral wedges from the graft to decrease rigidity. Patients in control group do not undergo the surgery. A 3-dimensional raster surface scanner was used to capture the images of the patients accurately and nasal mobility was measured. Subjective evaluations were carried out by a series of questionnaires asked to the patients. The angle α of nasal mobility was significantly lower in conventional grafting (23.09 [5.34] mm for silicone and 17.88 [4.96] mm for e-PTFE) versus the “V” carving (30.53 [3.76] mm for silicone and 23.77 [4.53] mm for e-PTFE; P < .05). The double “V” carving method is a simple, effective, and practical method for improving dynamic nasal outcomes in patient undergoing augmentation rhinoplasty.


2015 ◽  
Vol 821-823 ◽  
pp. 953-956
Author(s):  
Gemma Rius ◽  
Narcis Mestres ◽  
Osamu Eryu ◽  
Philippe Godignon

Graphene is a 2D material with potential for almost any purpose, thanks to a combination of excellent characteristics, e.g. high electrical conductivity. Graphene grown on SiC wafers is one of the promising routes for graphene integration into planar technology electronic applications. Synthesis is based on the decomposition of a SiC single crystal surface at high temperature, where Si-terminated SiC substrates require the formation of the C buffer layer. In spite of numerous experimental and theoretical works the understanding and control upon crucial factors such as step and terrace stability or surface roughening is far from been fully comprehended and then technologically optimized. We present experimental results on the deposition of graphene onto Si-terminated 6H-SiC. We analyze the effect of ex situ and in situ conditionings of the SiC surface in the thermal decomposition and reconstruction of the SiC terraces, toward higher control upon the growth process of graphene films.


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