A new approach to the design of high-Tc superconductors: Metallised interlayers

1996 ◽  
Vol 105 (5-6) ◽  
pp. 1379-1384 ◽  
Author(s):  
J. L. Tallon ◽  
C. Bernhard ◽  
Ch. Niedermayer ◽  
J. Shimoyama ◽  
S. Hahakura ◽  
...  
1991 ◽  
Vol 249 ◽  
Author(s):  
Rafael Hidalgo ◽  
Xin-Yu Zhanl ◽  
Sheng-Qi Wang ◽  
Baoshan Zhang ◽  
Jian-Zhong Zhang ◽  
...  

ABSTRACTA recently developed method for producing triaxial alignment of single crystalline grains may be applicable to ceramics other than the high-Tc cuprate superconductors for which it was designed as a means of reducing the grain boundary weak links due to grain orientational misfit. This technique uses a suitable combination of a mechanical force and a magnetic field acting on the moment of a rare earth element incorporated into the ceramic; a "granular single crystal" is thus formed. A detailed step-by-step procedure is presented here to facilitate use of the new approach.


1996 ◽  
Vol 4 (4) ◽  
pp. 191-194
Author(s):  
J. Jaklovszky ◽  
G. Aldica ◽  
C. Rusu ◽  
A. Crisan

1990 ◽  
Vol 165-166 ◽  
pp. 1275-1276 ◽  
Author(s):  
Peter Lemmens ◽  
Philipp Fröning ◽  
Siegfried Ewert ◽  
Joseph Pankert ◽  
Helga Passing ◽  
...  

Author(s):  
John Silcox

Determination of the microstructure and microchemistry of small features often provides the insight needed for the understanding of processes in real materials. In many cases, it is not adequate to use microscopy alone. Microdiffraction and microspectroscopic information such as EELS, X-ray microprobe analysis and Auger spectroscopy can all contribute vital parts of the picture. For a number of reasons, dedicated STEM offers considerable promise as a quantitative instrument. In this paper, we review progress towards effective quantitative use of STEM with illustrations drawn from studies of high Tc superconductors, compound semiconductors and metallization of H-terminated silicon.Intrinsically, STEM is a quantitative instrument. Images are acquired directly by detectors in serial mode which is particularly convenient for digital image acquisition, control and display. The VG HB501A at Cornell has been installed in a particularly stable electromagnetic, vibration and acoustic environment. Care has been paid to achieving UHV conditions (i.e., 10-10 Torr). Finally, it has been interfaced with a VAX 3200 work station by Kirkland. This permits, for example, the acquisition of bright field (or energy loss) images and dark field images simultaneously as quantitative arrays in perfect registration.


Author(s):  
Maryvonne Hervieu

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.


PIERS Online ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 110-114
Author(s):  
Tamio Endo ◽  
Hong Zhu ◽  
Takahisa Sakurada ◽  
Ajay K. Sarkar ◽  
Masanori Okada ◽  
...  

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