Plasma frequency determination in YBa2Cu3O6+x as a function of oxygen content

1989 ◽  
Vol 50 (18) ◽  
pp. 2895-2901 ◽  
Author(s):  
N. Bontemps ◽  
D. Fournier ◽  
A.C. Boccara ◽  
P. Monod ◽  
H. Alloul ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Plasma Frequency ◽  
Frequency Determination

Spectroscopy of High Tc Oxides and Plasma Frequency Determination

1990 ◽  
pp. 188-190
Author(s):  
N. Bontemps ◽  
D. Fournier ◽  
A. C. Boccara ◽  
P. Monod
Keyword(s):  
Plasma Frequency ◽  
High Tc ◽  
Frequency Determination

Plasma frequency in randomly oriented and textured ceramics YBa 2 Cu 3 O 6+x as a function of oxygen content

1989 ◽  
Vol 162-164 ◽  
pp. 1113-1114 ◽  
Author(s):  
N. Bontemps ◽  
D. Fournier ◽  
A.C. Boccara ◽  
P. Monod ◽  
H. Alloul ◽  
...  
Keyword(s):  
Oxygen Content ◽  
Plasma Frequency ◽  
Textured Ceramics

Magnetoresistive polyaniline–silicon carbide metacomposites: plasma frequency determination and high magnetic field sensitivity

2016 ◽  
Vol 18 (29) ◽  
pp. 19536-19543 ◽  
Author(s):  
Hongbo Gu ◽  
Jiang Guo ◽  
Mojammel Alam Khan ◽  
David P. Young ◽  
T. D. Shen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Silicon Carbide ◽  
High Magnetic Field ◽  
Plasma Frequency ◽  
Field Resistance ◽  
Negative Permittivity ◽  
Frequency Determination ◽  
Field Sensitivity

Both negative permittivity and high magnetic field resistance sensitivity are observed in silicon carbide/polyaniline nanocomposites.

scholarly journals Die Reflektivität von Rubidium- und Cäsium-Suboxiden

1985 ◽  
Vol 40 (4) ◽  
pp. 303-312 ◽  
Author(s):  
G. Metsch ◽  
W. Bauhofer ◽  
A. Simon
Keyword(s):  
Alkali Metal ◽  
Single Crystals ◽  
Oxygen Content ◽  
Plasma Frequency ◽  
Surface Plasma ◽  
Plasma Oscillations ◽  
Polarised Light

The reflectivity of single crystals of the alkali metal suboxides Cs7O, Cs4O, Cs11O3 und Rb9O2 has been measured with linearly polarised light in the range from 0.4 to 5 eV. The plasma frequency is derived as a function of the oxygen content by means of Kramers-Kronig analysis of the data. A Drude-Lorentz fit allows the assignment of additional structures in the spectra. These structures are discussed in terms of surface plasma oscillations, inter-band transitions from the 02p band and "void modes".

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

A study of oxygen and vacancy ordering in YBa2Cu3O7−x

1989 ◽  
Vol 47 ◽  
pp. 164-165
Author(s):  
Y. P. Lin ◽  
A. H. O’Reilly ◽  
J. E. Greedan ◽  
M. Post
Keyword(s):  
Electron Microscopy ◽  
Neutron Diffraction ◽  
Oxygen Content ◽  
Carbon Film ◽  
Nitrogen Atmosphere ◽  
Vacancy Ordering ◽  
Powder Samples ◽  
Vacancy Chains ◽  
Chain Ordering

In the basal planes of the orthorhombic YBa2Cu3O7-X compound with x=0.07, which has a Tc of around 90K, chains of copper-oxygen are formed along the [010] direction. Previous investigations on the variation of Tc with oxygen content have shown the existence of a plateau at Tc = 60K for x=0.3 to 0.4, suggesting the presence of a separate phase. This phase has also been identified to be orthorhombic, but with a 2x superlattice along [100] of the parent structure, and the superlattice has been attributed to the formation of alternating copper-oxygen and copper-vacancy chains. In our work, we have studied the chain ordering phenomenon by electron microscopy and neutron diffraction on samples with different oxygen contents. We report here some of our electron microscopy findings for samples with x=0.4.Powder samples of YBa2Cu3O7-X were prepared by controlled re-oxidation of previously reduced material. For electron microscopy, the sample was dry ground using a mortar and pestle in a dry nitrogen atmosphere without the use of any solvent and transferred dry onto holey carbon film for examination in a Philips CM12 microscope.

The biochemistry of drugs and doping methods used to enhance aerobic sport performance

2008 ◽  
Vol 44 ◽  
pp. 63-84 ◽  
Author(s):  
Chris E. Cooper
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Content ◽  
Oxygen Delivery ◽  
Sport Performance ◽  
Blood Substitutes ◽  
Altitude Training ◽  
Blood Oxygen ◽  
Oxygen Carriers ◽  
Sports Performance ◽  
Blood Doping

Optimum performance in aerobic sports performance requires an efficient delivery to, and consumption of, oxygen by the exercising muscle. It is probable that maximal oxygen uptake in the athlete is multifactorial, being shared between cardiac output, blood oxygen content, muscle blood flow, oxygen diffusion from the blood to the cell and mitochondrial content. Of these, raising the blood oxygen content by raising the haematocrit is the simplest acute method to increase oxygen delivery and improve sport performance. Legal means of raising haematocrit include altitude training and hypoxic tents. Illegal means include blood doping and the administration of EPO (erythropoietin). The ability to make EPO by genetic means has resulted in an increase in its availability and use, although it is probable that recent testing methods may have had some impact. Less widely used illegal methods include the use of artificial blood oxygen carriers (the so-called ‘blood substitutes’). In principle these molecules could enhance aerobic sports performance; however, they would be readily detectable in urine and blood tests. An alternative to increasing the blood oxygen content is to increase the amount of oxygen that haemoglobin can deliver. It is possible to do this by using compounds that right-shift the haemoglobin dissociation curve (e.g. RSR13). There is a compromise between improving oxygen delivery at the muscle and losing oxygen uptake at the lung and it is unclear whether these reagents would enhance the performance of elite athletes. However, given the proven success of blood doping and EPO, attempts to manipulate these pathways are likely to lead to an ongoing battle between the athlete and the drug testers.

Multi-rating Electronic Ballast for Fluorescent Lamps based on Operating Frequency Determination

2011 ◽  
Vol 131 (10) ◽  
pp. 1184-1192
Author(s):  
Piyasawat Navaratana Na Ayudhya ◽  
Sumate Naetiladdanon ◽  
Anawach Sangswang
Keyword(s):  
Operating Frequency ◽  
Electronic Ballast ◽  
Frequency Determination ◽  
Fluorescent Lamps

Silicon Surface Chemical Treatments in Oxide/Nitride Dielectric Stack Properties

2002 ◽  
Vol 716 ◽  
Author(s):  
D. Jacques ◽  
S. Petitdidier ◽  
J.L. Regolini ◽  
K. Barla
Keyword(s):  
Oxygen Content ◽  
Oxide Thickness ◽  
Morphological Data ◽  
Electrical Characteristics ◽  
Electrical Measurements ◽  
Chemical Cleaning ◽  
Force Microscopy ◽  
Chemical Treatments ◽  
Atomic Force ◽  
Interfacial Oxygen

AbstractOxide/Nitride dielectric stack is widely used as the standard dielectric for DRAM capacitors. The influence of the chemical cleaning prior to the stack formation has been studied in this work. As a result, morphological data such as stack surface roughness (Atomic Force Microscopy) and silicon nitride (SiN) incubation time for growth are comparable for all the studied cases on <Si>. However, Tof-SIMS exhibits different oxygen content at the Si/stack interface following the different chemical treatments. Electrical measurements show comparable C-V and I-V results, for the same Equivalent Oxide Thickness (same capacitance at strong accumulation i.e.-3V) while the different studied interfaces bring different interface states density with lower values for higher interfacial oxygen content. For DRAM applications, a clear improvement in electrical characteristics is obtained under low interfacial oxygen content conditions. Results are compared in embedded-DRAM cells for which we developed an industrially compatible dielectric deposition sequence to obtain minimum leakage current with maximum specific capacitance and no particular linking constraints.

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