Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Electron microscopy and microanalysis of a YBa2Cu3Ox superconducting oxide (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 535-537 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The onset of superconductivity at 140 K has been observed in the high Tc Y-Ba-Cu-O system in samples consisting of 90% by volume of a single-phase oxide of average cation ratio Y:Ba:Cu(approximately-equal-to)1:2:3. A sharp superconducting transition in the resistivity has been measured, where Tc0=140 K, Tc=93.2 K, ΔTc=0.5 K, and "zero resistance'' was observed at 92.0 K. Transmission electron microscopy and energy dispersive spectroscopy measurements revealed that the superconducting phase consisted of a large number of microcrystallites of (approximately-equal-to)0.5 μm size and that these contained a very high defect microtwinned/faulted structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.98390
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Critical currents in silver-sheathed (Bi,Pb)2Sr2Ca2Cu3O10−y superconducting tapes (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 3171-3173 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nearly 95 vol % of the 110 K superconducting phase was formed by lead doping in a Bi–Sr–Ca–Cu–O system. The processed 110 K superconducting powders were used to produce long silver-sheathed tapes with a highly textured microstructure by rolling and prolonged sintering. The transport critical current density was measured at 4.0 K to be 0.7×105 A/cm2 (the corresponding critical current is 74 A) at zero field and 1.6×104 A/cm2 at 12 T for H(parallel)ab. At 76 K, the critical current density reached a value of ∼1×104 A/cm2 at zero field for H(parallel)ab and gradually decreased to 419 A/cm2 at 1 T. Excellent grain alignment in the a–b plane led to greatly improved critical current densities under a magnetic field. The relationship between the transport properties and the microstructure of the tapes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105774
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Superconductivity in a Ag-doped Bi-Pb-Sr-Ca-Cu-O system (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 493-494 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: For the Bi-Pb-Sr-Ca-Cu-O (BPSCCO) system, a consistent set of data for Tc, x-ray diffraction, and scanning electron microscopy shows that Ag additions strongly react with BPSCCO to destabilize the 110 K superconducting phase, resulting in a strong depression in Tc and lattice parameters when samples are treated in air or pure oxygen. This is in contrast to the behavior for the Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O systems, which do not show such degradation. However, Ag additions show no effects on Tc and lattice parameters when samples are treated under low oxygen pressure. The formation of a low-melting eutectic liquid with Ag2O-PbO-CuO solid solution affects the composition of the superconducting phase and degrades superconductivity, while the eutectic may be suppressed by reducing the oxygen partial pressure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.103298
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effect of silver addition on superconductivity in the Bi1.6Pb0.4Sr1.6Ca2Cu3O10−y system (1990)
    Springer
    Journal of materials science 1 (1990), S. 30-33 
    Details
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Silver/superconductor composites containing 0 to 80 vol% silver have been prepared and their properties determined. Optimum heat treatment at sintering temperatures (∼ 800° C) under low oxygen pressures produces material with high critical current density and improves physical properties. Magnetic susceptibility measurements have been found to be consistent with resistivity results. In order to retain a single high-T c phase with increasing silver content, decreased oxygen partial pressures are required. Using the normal-state resistivity of these composites, a percolation threshold at a silver volume fraction of ∼43% was observed, while zero resistivity measurements show that a continuous superconducting network can be obtained with up to ∼80 vol% silver. The critical current density of 21 vol% silver-doped samples was found to be 1520 A cm−2 at 77.3 K, compared to 260 A cm−2 for an undoped sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00716013
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Chemical diffusion of (La,Sr)CoO3 and (La,Sr)FeO3 (2000)
    Springer
    Journal of materials science 11 (2000), S. 691-696 
    Details
    ISSN: 1573-482X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The present work reports equilibration kinetics for (La0.8,Sr0.2)CoO3(LSC) and (La0.72,Sr0.18)FeO3(LSF) in the temperature range 876–1114 K using a gravimetric method. Chemical diffusion determined in this way that depends on oxygen partial pressure, can be expressed by the following temperature dependence at low and high O2), respectively, for LSC: $$D_{chem} = 8.7 \times 10^{ - 3} {\text{exp}}\frac{{{\text{ - }}\left( {58.1 \pm 8.5} \right){\text{kJ/mol}}}}{{RT}}({\text{cm}}^{\text{2}} {\text{s}}^{{\text{ - 1}}} ){\text{ (1)}}$$ $$D_{chem} = 6.2 \times 10^{ - 3} {\text{exp}}\frac{{{\text{ - }}\left( {75.4 \pm 6.5} \right){\text{kJ/mol}}}}{{RT}}({\text{cm}}^{\text{2}} {\text{s}}^{{\text{ - 1}}} ){\text{ (2)}}$$ and for LSF: $$D_{chem} = 3.05 \times 10^{ - 5} {\text{exp}}\frac{{{\text{ - }}\left( {30.3 \pm 2.8} \right){\text{kJ/mol}}}}{{RT}}({\text{cm}}^{\text{2}} {\text{s}}^{{\text{ - 1}}} ){\text{ (3)}}$$ $$D_{chem} = 6.3 \times 10^{ - 3} {\text{exp}}\frac{{{\text{ - }}\left( {82.7 \pm 10.2} \right){\text{kJ/mol}}}}{{RT}}({\text{cm}}^{\text{2}} {\text{s}}^{{\text{ - 1}}} ){\text{ (4)}}$$
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008926809900
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Interfacial bond strength of electrophoretically deposited hydroxyapatite coatings on metals (1999)
    Springer
    Journal of materials science 10 (1999), S. 401-409 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract Hydroxyapatite (HAp) coatings were deposited onto substrates of metal biomaterials (Ti, Ti6Al4V, and 316L stainless steel) by electrophoretic deposition (EPD). Only ultra-high surface area HAp powder, prepared by the metathesis method 10Ca(NO3)2 + 6(NH4)2HPO4 + 8NH4OH), could produce dense coatings when sintered at 875–1000°C. Single EPD coatings cracked during sintering owing to the 15–18% sintering shrinkage, but the HAp did not decompose. The use of dual coatings (coat, sinter, coat, sinter) resolved the cracking problem. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) inspection revealed that the second coating filled in the “valleys” in the cracks of the first coating. The interfacial shear strength of the dual coatings was found, by ASTM F1044-87, to be ∼12 MPa on a titanium substrate and ∼22 MPa on 316L stainless steel, comparing quite favorably with the 34 MPa benchmark (the shear strength of bovine cortical bone was found to be 34 MPa). Stainless steel gave the better result since α-316L (20.5 μm mK-1) 〉 α-HAp (∼14 μm mK-1), resulting in residual compressive stresses in the coating, whereas α-titanium (∼10.3 μm mK-1) 〈 α-HAp, resulting in residual tensile stresses in the coating. © 1999 Kluwer Academic Publishers
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008923029945
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The effects of sintering atmosphere on the chemical compatibility of hydroxyapatite and particulate additives at 1200°C (1995)
    Springer
    Journal of materials science 6 (1995), S. 297-301 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: According to Le Chatelier's principle, dehydration and the associated decomposition of hydroxyapatite (HAP) to biodegradable unhydrated calcium phosphates during sintering may be suppressed under a moist sintering atmosphere (thermodynamic effect), or possibly under a pressurized sintering atmosphere (physical effect), by opposing the release of water. The present study explored this possibility. High-purity powdered additives were used to minimize impurity and morphological effects. Al2O3, C, SiC, SiO2, ZrO2, and 316L stainless steel were all trialled at an addition level of 20 vol%. Heat treatment was at 1200°C for 1 h under two experimental atmospheres and two corresponding control atmospheres: flowing H2O/O2 mix—ambient air as a control; pressurized (1 MPa) argon—ambient argon (0.1 MPa) as a control. Specimens were analysed for decomposition by X-ray diffraction (XRD), for densification by porosity measurement, and for microstructural uniformity by energy dispersive spectroscopy (EDS) and image analysis. Significant decomposition occurred under all atmospheres with the exception of flowing H2O/O2 which eliminated decomposition in the HAP-Al2O3, HAP-ZrO2, and HAP-316L systems, and reduced the decomposition levels from near completion to ∼50% in the HAP-SiC and HAP-SiO2 systems. Moistureless pressurization had little effect. Microstructural uniformity was confirmed. No generalized atmosphere-densification interrelationships were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00120274
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Work Function of PbZrO3 (1998)
    Springer
    Journal of materials synthesis and processing 6 (1998), S. 335-338 
    Details
    ISSN: 1573-4870
    Keywords: PbZrO3 ; oxidation ; nonstoichiometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper reports the results of work function (WF) changes of undoped PbZrO3 during subsequent isothermal oxidation and reduction experiments at 500°C in the p(O2) range between 10 and 2.1 × 104 Pa. The results, obtained during three consecutive runs, indicate that heating at 500°C leads to continuous changes of surface properties resulting in a complex WF vs. time characteristic. The WF changes during the first oxidation are determined by a p(O2)-induced structural transition. The second oxidation results in two competitive processes, such as rapid increase of oxygen non-stoichiometry followed by a structural transition. Finally, the third oxidation is determined by changes of oxygen nonstoichiometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022603327570
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effect of Surface Preparation of Zirconia on its Reactivity with Oxygen (1998)
    Springer
    Journal of materials synthesis and processing 6 (1998), S. 373-377 
    Details
    ISSN: 1573-4870
    Keywords: Zirconia ; oxidation ; preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper reports surface electrical properties of zirconia studied using work function measurements in the temperature range 297–1173 K during oxidation. It was found that surface preparation procedures, such as grinding and polishing, result in a change of its reactivity with oxygen. The effects produced by the preparation can be removed during thermal treatment at 1473 K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1021820720142
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Twins, kinks and cracks in dense superconducting YBa2Cu3O7−x (1989)
    Springer
    Journal of materials science 8 (1989), S. 1147-1150 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01730051
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...