scholarly journals Experimental Set-Up for Evaluation of Electro-Magnetic Characteristics of High-Tc Superconductors Cooled by Liquid Hydrogen

2013 ◽  
Vol 23 (3) ◽  
pp. 9500404-9500404 ◽  
Author(s):  
Y. Shirai ◽  
K. Hikawa ◽  
M. Shiotsu ◽  
H. Tatsumoto ◽  
K. Hata ◽  
...  
Keyword(s):  
Liquid Hydrogen ◽  
Magnetic Characteristics ◽  
High Tc Superconductors ◽  
High Tc ◽  
Electro Magnetic ◽  
Set Up

Structural and Magnetic Characteristics of (Eu1-xGax) Ba2Cu3O7-δ High-Tc Superconductors

1997 ◽  
Vol 11 (13) ◽  
pp. 593-597 ◽  
Author(s):  
Iuliu Pop ◽  
Radu Redac ◽  
Gheorghe Borodi ◽  
Virgil Ioncu
Keyword(s):  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Tetragonal Structure ◽  
Magnetic Characteristics ◽  
High Tc Superconductors ◽  
High Tc ◽  
Gallium Concentration ◽  
Paramagnetic Region ◽  
Diamagnetic Transition

The high-T c ( Eu 1-x Ga x) Ba 2 Cu 3 O 7-δ superconductors with x=0, 0.01, 0.02, 0.03, 0.06 and 0.09 were synthesized by a ceramic technique. The gallium concentration dependence of the lattice parameters was determined. A transition from orthorhombic toward tetragonal structure was relevated for the most gallium concentrated sample. The temperature dependence of the magnetic susceptibility pointed out the diamagnetic transition at 78 and 80 K. In the paramagnetic region the magnetic susceptibility exhibits anomal temperature dependence.

Pair Symmetry and Degree of Gap Depression at S-I Interfaces in HTS Josephson Junctions

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1301-1306
Author(s):  
G. A. Ummarino ◽  
R. S. Gonnelli ◽  
C. Bravi ◽  
Masumi Inoue
Keyword(s):  
Josephson Junctions ◽  
Order Parameter ◽  
Reference Value ◽  
High Tc Superconductors ◽  
S Wave ◽  
General Reference ◽  
High Tc ◽  
Wave Symmetry ◽  
Set Up ◽  
D Wave

A new possible indirect way of testing pair symmetry in high-Tc superconductors has been set up. The degree of intrinsic gap depression at Superconductor-Insulator [S-I] interfaces required to match Ic(T)Rn(T) data in HTS Josephson junctions depends on the pair symmetry of the material itself, so that an higher fraction of d-wave symmetry for the order parameter requires less gap depression, while an higher fraction of s-wave corresponds to a larger degree of gap depression. In order to obtain a general reference value for the intrinsic amount of gap depression at S-I interfaces the de Gennes condition has been used, and resulting reduced Ic(T)Rn(T) data have been calculated in the framework of a mixed (s+id)-wave pair symmetry for the depressed order parameter ranging from pure s to pure d-wave. This model has been tentatively applied to two junctions' made of very different HTSs: YBCO and BKBO, yielding a result of almost pure d-wave for YBCO and of pure s-wave for BKBO.

scholarly journals Development of a thermal-hydraulics experimental system for high Tc superconductors cooled by liquid hydrogen

2010 ◽  
Vol 234 (3) ◽  
pp. 032056 ◽  
Author(s):  
H Tatsumoto ◽  
Y Shirai ◽  
M Shiotsu ◽  
K Hata ◽  
H Kobayashi ◽  
...  
Keyword(s):  
Experimental System ◽  
Liquid Hydrogen ◽  
Thermal Hydraulics ◽  
High Tc Superconductors ◽  
High Tc

The many faces of STEM in materials science

1991 ◽  
Vol 49 ◽  
pp. 440-441
Author(s):  
John Silcox
Keyword(s):  
Materials Science ◽  
Auger Spectroscopy ◽  
Dark Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Acoustic Environment ◽  
Electromagnetic Vibration ◽  
The Many ◽  
Serial Mode

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.

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

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.

Sign in / Sign up

Export Citation Format

Share Document