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.

MAGNETIC PROPERTIES OF Yb1-xGaxBa2Cu3O7-δ HIGH TC SUPERCONDUCTORS

2008 ◽  
Vol 22 (21) ◽  
pp. 3677-3682
Author(s):  
IULIU POP ◽  
CARMEN SBÂRCIOG ◽  
OVIDIU POP
Keyword(s):  
Magnetic Susceptibility ◽  
Curie Constant ◽  
Thermal Variation ◽  
High Tc Superconductors ◽  
High Tc ◽  
Static Magnetic Susceptibility ◽  
X Ray ◽  
Paramagnetic Region ◽  
Valence States ◽  
Superconducting Compounds

The thermal variation of the static magnetic susceptibility, for the Yb 1-x Ga x Ba 2 Cu 3 O 7-δ, x = 0.00; 0.01; 0.02; 0.03; 0.06 oxidic high TC superconductors was investigated. In the paramagnetic region, the reciprocal magnetic susceptibility temperature dependence is nonlinear, obeying the hyperbolic Neel law, valid for the ferromagnetic collinear magnetic structure. The effective magnetic moment value determined from the Curie constant is a giant one, suggesting the existence of Cu 3+ and Yb 6+ valence states in high TC superconducting compounds. The structural X-ray investigation revealed a homogeneous orthorhombic crystalline structure in Yb 1-x Ga x Ba 2 Cu 3 O 7-δ superconducting compounds.

NANOSCOPIC PHASE SEPARATION AND THE UNIVERSAL TRANSPORT AND MAGNETIC PROPERTIES OF HIGH Tc SUPERCONDUCTORS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3528-3531
Author(s):  
J. JUNG ◽  
H. YAN ◽  
H. DARHMAOUI ◽  
M. ABDELHADI
Keyword(s):  
Magnetic Properties ◽  
Phase Separation ◽  
Temperature Dependence ◽  
Current Density ◽  
Low Temperatures ◽  
Energy Barrier ◽  
Vortex Motion ◽  
Superfluid Density ◽  
High Tc Superconductors ◽  
High Tc

We have found the correlation between nanoscopic phase separation in the copper-oxygen planes of YBCO and TlBCCO and the transport and magnetic properties of these materials in the a-b planes such as: the temperature dependence of the critical current density Jc( T ), the temperature dependence of the superfluid density ns( T )∝1/λ2( T ) at low temperatures, the temperature dependence of the normalized logarithmic relaxation rate S(T), and the dependence of the effective energy barrier against vortex motion on the current density Ueff( J ). These properties are controlled by the ratio of the amount of an underdoped filamentary phase to that of an optimally doped one.

Temperature dependence of the critical current in high-Tc superconductors with low-angle boundaries between crystalline blocks

2001 ◽  
Vol 27 (2) ◽  
pp. 96-102 ◽  
Author(s):  
É. A. Pashitskiı̆ ◽  
V. I. Vakaryuk ◽  
S. M. Ryabchenko ◽  
Yu. V. Fedotov
Keyword(s):  
Temperature Dependence ◽  
Critical Current ◽  
High Tc Superconductors ◽  
High Tc

Temperature dependence of the low field microwave absorption of high Tc superconductors

1988 ◽  
Vol 133 (6) ◽  
pp. 339-341 ◽  
Author(s):  
A.R. Harutyunyan ◽  
L.S. Grigoryan ◽  
M. Baran ◽  
S. Piechota
Keyword(s):  
Temperature Dependence ◽  
Microwave Absorption ◽  
High Tc Superconductors ◽  
High Tc ◽  
Low Field

MICROWAVE ABSORPTION STUDIES ON HIGH-Tc SUPERCONDUCTORS AND RELATED MATERIALS VII — ESR OF DPPH COATED ON A THIN BiSrCaCuO FILM FABRICATED ON MgO(100) SUBSTRATE

1992 ◽  
Vol 06 (11) ◽  
pp. 675-682
Author(s):  
K. SUGAWARA ◽  
T. SUGIMOTO ◽  
Y. SHIOHARA ◽  
S. TANAKA
Keyword(s):  
Magnetic Field ◽  
Critical Current Density ◽  
Temperature Dependence ◽  
Microwave Absorption ◽  
Current Density ◽  
Applied Magnetic Field ◽  
High Tc Superconductors ◽  
High Tc ◽  
Absorption Studies ◽  
Mpmg Method

ESR of DPPH coated on a Bi-Sr-Ca-Cu-O (BSCCO) film (350 Å thick) fabricated on MgO(100) substrate by MOCVD was studied. Temperature dependence of the ESR peak-to-peak linewidth, ΔH pp , and the effect of applied magnetic field on ΔH pp have been studied below about 100 K. The results were compared with those of ESR of DPPH coated on ceramic Y-Ba-Cu-O samples (powder and bulk) made by the MPMG method. The DPPH ESR for the BSCCO film revealed that ΔH pp was independent of applied magnetic field up to about 9 kG. In addition, no similarity between the temperature dependence of the excess ESR linewidth of the DPPH and that of critical current density was found for the BSCCO film. These results for the BSCCO film are different from those for the MPMG YBCO samples.

Temperature dependence of Cu-NQR frequencies and linewidths of high-Tc superconductors

1993 ◽  
Vol 209 (1-3) ◽  
pp. 59-61
Author(s):  
J. Freytag ◽  
M. Baenitz ◽  
S. Gärtner ◽  
H. Riesemeier ◽  
V. Müller ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
High Tc Superconductors ◽  
High Tc

43Ca NMR Study of Bismuth-Based High-Tc Superconductors

1994 ◽  
Vol 49 (1-2) ◽  
pp. 373-378 ◽  
Author(s):  
A. Trokiner ◽  
L. Le Noc ◽  
A. Yakubovskii ◽  
K.N. Mykhalyov ◽  
S.V. Verkhovskii
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Electronic Properties ◽  
High Tc Superconductors ◽  
High Tc ◽  
Structural Assignment ◽  
Bismuth Compounds ◽  
Nmr Study

Abstract As a first step of a study of the electronic properties of CuO2 planes by probing calcium nuclei in the bismuth-based high-Tc materials we report here the structural assignment of Ca NMR lines measured in 43Ca-enriched samples of n = 2 ((Bi,Pb)2Sr2CaCu2O8+x) and n = 3 ((Bi,Pb)2Sr2-Ca2Cu3O10+x) bismuth compounds. Powdered samples were investigated as well as oriented pow­ ders, achieved by uniaxial alignment of the grains in a 7T magnetic field. For the main calcium site (Ca between two CuO2 planes), we could determine the quadrupolar as well as the shift tensors. The results indicate that, in the same way as yttrium nuclei in YBaCuO, calcium nuclei are sensitive to the magnetic susceptibility of the metallic CuO2 planes.

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