High Jc YBa2Cu3O7-δ films via rapid, low pO2 pyrolysis

2001 ◽  
Vol 16 (1) ◽  
pp. 13-16 ◽  
Author(s):  
J. T. Dawley ◽  
P. G. Clem ◽  
M. P. Siegal ◽  
D. L. Overmyer

In this investigation YBa2Cu3O7-δ (YBCO) films were fabricated via a metal acetate, trifluoroacetic acid based sol-gel route and spin-coat deposited on (100) LaAlO3 with a focus on maximizing Jc, while minimizing processing time. We demonstrate that the use of a low-pO2 atmosphere during the pyrolysis stage can lead to at least a tenfold reduction in pyrolysis time, compared to a 1 atm O2 ambient. High-quality YBCO films on LaAlO3, with Jc values up to 3 MA/cm2 at 77 K, can be routinely crystallized from these rapidly pyrolyzed films.

2002 ◽  
Vol 17 (8) ◽  
pp. 1900-1903 ◽  
Author(s):  
J. T. Dawley ◽  
P. G. Clem ◽  
M. P. Siegal ◽  
D. R. Tallant ◽  
D. L. Overmyer

The effect of high-boiling-point solvent addition on the morphology of low-p(O2) processed, sol-gel YBa2Cu3O7−δ (YBCO) films is discussed. Proper selection and addition of a high-boiling-point solvent prevents film roughening during precursor pyrolysis, while permitting at least a tenfold reduction in pyrolysis time compared to standard film processing in air or O2. Use of such solvents appears to increase film plasticity, avoiding elastic compressive stress related buckling. High-quality YBCO films on 〈100〉 LaAlO3 with a critical current density (Jc) ∼ 3–4 MA/cm2 at 77 K, are routinely crystallized with this new sol-gel process. Diethanolamine-based, sol-gel YBCO films deposited on sol-gel SrTiO3-buffered 〈100〉 Ni have Jc(77 K) > 1 MA/cm2, demonstrating a route toward all-sol-gel superconducting wires.


2002 ◽  
Vol 17 (6) ◽  
pp. 1543-1549 ◽  
Author(s):  
S. Sathyamurthy ◽  
M. Paranthaman ◽  
T. Aytug ◽  
B. W. Kang ◽  
P. M. Martin ◽  
...  

Sol-gel processing of La2Zr2O7 (LZO) buffer layers on biaxially textured Ni–1.7% Fe–3% W alloy substrates using a continuous reel-to-reel dip-coating unit has been studied. The epitaxial LZO films obtained have a strong cube texture and uniform microstructure. The effects of increasing the annealing speed on the texture, microstructure, and carbon content retained in the film were studied. On top of the LZO films, epitaxial layers of yttria-stabilized zirconia and Ceria (CeO2) were deposited using rf sputtering, and YBa2Cu3Ox (YBCO) films were then deposited using pulsed laser deposition. Critical current densities (Jc) of 1.9 MA/cm2 at 77 K and self-field and 0.34 MA/cm2at 77 K and 0.5 T have been obtained on these films. These values are comparable to those obtained on YBCO films deposited on all-vacuum deposited buffer layers and the highest ever obtained using solution seed layers.


2008 ◽  
Vol 468 (21) ◽  
pp. 2213-2218 ◽  
Author(s):  
Guoxing Li ◽  
Xiujun Fang ◽  
Lei Zhao ◽  
Shanwen Li ◽  
Zhongmin Gao ◽  
...  

2015 ◽  
Vol 3 (9) ◽  
pp. 2115-2122 ◽  
Author(s):  
Wei Sun ◽  
Jing-Feng Li ◽  
Qi Yu ◽  
Li-Qian Cheng

We prepared high-quality Bi1−xSmxFeO3 films on Pt(111)/Ti/SiO2/Si substrates by sol–gel processing and found rhombohedral–orthorhombic phase transition with enhanced piezoelectricity.


2020 ◽  
Vol 14 (4) ◽  
pp. 535-544
Author(s):  
Andreas Bretz ◽  
Eberhard Abele ◽  
Matthias Weigold

Abstract Reaming plays a crucial role in production to meet the high quality requirements of precision bore machining. It is either directly responsible for the final component quality or influences subsequent processes such as honing. The narrow tolerances are usually monitored by measuring random samples in mass production due to cost efficiency. Having a closer look at an exemplary process chain for the production of hydraulic valves shows the possibility to adapt the honing parameters which reduces processing time and costs. However, the bore straightness after the reaming process has to be known. In this paper an approach is presented which allows to record the bore straightness within the productive time. For this purpose, a sensory reaming system is developed. It can be used without additional components in the machine tool and thus integrated into existing machining processes. Cutting tests show that the system is able to measure the bore straightness as good as sensing probes used in machine tools.


1994 ◽  
Vol 9 (10) ◽  
pp. 2703-2705 ◽  
Author(s):  
Fengqing Wu ◽  
David Machewirth ◽  
Elias Snitzer ◽  
George H. Sigel

High quality Nd-doped single-mode fibers have been prepared by using a sol-gel process. The longest fluorescence lifetime measured was 520 μs in an Al: SiO2 glass fiber containing 0.47 wt.% neodymium oxide. An efficient neodymium fiber laser with a slope above threshold of 42% was successfully demonstrated with the sol-gel prepared Nd-doped single-mode fibers as a fiber laser oscillator.


2020 ◽  
Author(s):  
Christiane Adler ◽  
Igor Krivtsov ◽  
Dariusz Mitoraj ◽  
Lucía dos Santos-Gómez ◽  
Santiago García-Granda ◽  
...  

In spite of the enormous promise that polymeric carbon nitride (PCN) materials hold for photoelectrochemical (PEC) applications, the fabrication of high-quality PCN photoelectrodes has been a largely elusive goal to date. Here we tackle this challenge by devising, for the first time, a sol–gel approach that enables facile preparation of photoanodes based on poly(heptazine imide) (PHI), a polymer belonging to the PCN family. The sol–gel process capitalizes on the use of a water-soluble PHI precursor composed of nanosized (~10 nm) particles that allows formation of a non-covalent hydrogel. The hydrogel can be deposited on a conductive substrate resulting in formation of mechanically stable porous polymeric thin layers (~400 nm), in contrast to the commonly obtained loosely attached thick particulate coatings. The resulting photoanodes exhibit unprecedented PEC performance in methanol reforming in neutral pH electrolytes with photocurrents of up to 177±27 mA cm<sup>-2</sup> (1 sun illumination) and 320±40 mA cm<sup>-2</sup> (2 sun illumination) at 1.23 V vs. RHE, maintaining such high photocurrents even down to ~0 V vs. RHE. These parameters permit effective operation even without any external electric bias, as demonstrated by bias-free photoreforming of methanol and glycerol, and highly selective (~100%) photooxidation of 4-methoxybenzyl alcohol (4-MBA). The robust binder-free films derived from sol–gel processing of water-soluble PCN thus represent a new paradigm for high-performance ‘soft-matter’ photoelectrocatalytic systems, and pave the way for further applications in which high-quality PCN films are required.


2015 ◽  
Vol 55 (1) ◽  
pp. 113 ◽  
Author(s):  
Eva Salazar ◽  
Adela Abellán ◽  
José M. Cayuela ◽  
Ángel Poto ◽  
Francisco Girón ◽  
...  

The compositional and sensory parameters of Chato Murciano dry-cured ham at different ripening times (14, 18, 22 and 24 months of processing) were studied. A sensory consumer study of dry-cured ham with a short ripening stage (14 months of processing) and a similar ham with a long ripening stage (22 months of processing) was carried out. Dry-cured hams remained in the ripening stage at 18−20°C and 70–75% relative humidity. The different processing times studied had no effect on the ash, intramuscular fat, sodium chloride and protein contents of the final ham, but significantly affected the moisture (P < 0.05) and saturated (P < 0.01) and monounsaturated (P < 0.05) fatty acid contents. Sensory analysis showed that processing time enhanced redness, fat colour, all of the odour and flavour traits studied, and all the texture traits except juiciness. In the taste profile, only saltiness showed a significant increase. However, sensory changes were only significant up to 22 months of processing (for most of the parameters), the resulting ham showing higher level of consumer preference and acceptability than dry-cured ham with the shorter ripening. Based on these results, it is recommended that an appropriate processing time to obtain a high-quality Chato Murciano dry-cured ham is 22 months.


2007 ◽  
Vol 546-549 ◽  
pp. 2007-2010
Author(s):  
Gao Yang Zhao ◽  
Huang Li Zhang ◽  
Ren Zhong Xue ◽  
Yuan Qing Chen ◽  
Li Lei

precursor solution was prepared using barium trifluoroacetae (Ba-TFA) and non-fluorine yttrium (Y) and copper (Cu) organic salts. The precursor solution was modified by benzalacetone (BzAcH), in which the Cu2+ were chelated with BzAcH, which preventing the loss of Cu in the pyrolysis process. Dense YBCO superconducting films with smooth surface, which confirmed by scanning electron microscopy (SEM), were repeatedly obtained through sol-gel process. X-ray diffraction (XRD) 2θ scanning and φ scanning indicated that the as-prepared YBCO films had good c-axis texture. YBCO films with superconducting transition temperature (TC) above 89K were obtained.


2020 ◽  
Vol 49 (7) ◽  
pp. 4186-4194
Author(s):  
I. B. T. Silva ◽  
A. G. D’assunção ◽  
J. B. L. Oliveira ◽  
J. R. F. Guerra ◽  
C. H. N. Cordeiro

Sign in / Sign up

Export Citation Format

Share Document