scholarly journals Zinc Nanoparticles at Intercrystallite Sites of (Cu0.5Tl0.5)Ba2Ca3Cu4O12−δSuperconductor

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Irfan Qasim ◽  
M. Mumtaz ◽  
K. Nadeem ◽  
S. Qamar Abbas
Keyword(s):  
Crystal Structure ◽  
Critical Temperature ◽  
Solid State ◽  
Cross Section ◽  
Normal State ◽  
Superconducting Properties ◽  
Normal State Resistivity ◽  
Solid State Reaction Technique ◽  
Zinc Nanoparticles ◽  
Zn Nanoparticles

We synthesizedZnx/(Cu0.5Tl0.5)Ba2Ca3Cu4O12-δ  {Znx/CuTl-1234}(x= 0~3 wt.%)nanoparticles-superconductor composites by solid-state reaction technique and examined the effects of zinc (Zn) nanoparticles on structural and superconducting properties of CuTl-1234 phase. Unaltered crystal structure of host CuTl-1234 phase confirmed the existence of Zn nanoparticles at intercrystallite sites. We observed an improvement in grains size and intergrains connectivity by healing up the voids after incorporation of Zn nanoparticles in CuTl-1234 superconductor. Superconducting properties ofZnx/CuTl-1234 composites were suppressed for all Zn nanoparticles concentrations. Suppression of zero resistivity critical temperature{Tc(0)}and variation in normal state resistivity{ρ300 K (Ω-cm)}were attributed to reduction of superconducting volume fractions and enhanced scattering cross section of mobile carriers.

Correlation between superconducting critical temperature and normal-state resistivity parameters from the codopedErBa2Cu3−x−yZnxFeyO7−δsystem

2000 ◽  
Vol 61 (17) ◽  
pp. 11752-11761 ◽  
Author(s):  
Anurag Gupta ◽  
Ratan Lal ◽  
A. Sedky ◽  
A. V. Narlikar ◽  
V. P. S. Awana
Keyword(s):  
Critical Temperature ◽  
Normal State ◽  
Normal State Resistivity

A POSSIBLE CORRELATION BETWEEN SUPPRESSION OF SUPERCONDUCTIVITY, MAGNETIC ORDERING AND NORMAL STATE RESISTIVITY PARAMETERS IN THE Yb1-xPrxBa2Cu3O7-δ SYSTEM

2002 ◽  
Vol 16 (08) ◽  
pp. 261-273 ◽  
Author(s):  
ANURAG GUPTA ◽  
H. NARAYAN ◽  
P. N. LISBOA-FILHO ◽  
C. A. CARDOSO ◽  
FERNANDO M. ARAUJO MOREIRA ◽  
...  
Keyword(s):  
Critical Temperature ◽  
Normal State ◽  
Magnetic Ordering ◽  
Residual Resistivity ◽  
Gradual Decrease ◽  
Normal State Resistivity ◽  
Characteristic Temperatures ◽  
Antiferromagnetic Ordering ◽  
Diamagnetic Transition ◽  
The Difference

Polycrystalline samples of the Pr doped Yb 1-x Pr x Ba 2 Cu 3 O 7-δ (i.e. Yb(Pr)-123) system for 0≤x≤1 have been investigated for resistivity ρ and magnetization M as a function of temperature in normal and superconducting states. The gradual decrease in superconducting critical temperature T c (x) is found to be correlated with the x-dependent ratio of resistivity slope (dρ/dT) cc (corresponding to the linear ρ(T) region) and residual resistivity ρ0. In particular, the observed difference of critical Pr concentration where superconductivity is destroyed (x c ) in Yb(Pr)-123 (x c ≈ 0.65) and Y(Pr)-123 (x c ≈ 0.55) matches with the difference in the value of Pr concentration where the ratio (dρ/dT) cc /ρ0 tends to go to zero in them. The M(T) data of the Yb(Pr)-123 samples show magnetic ordering for x > x c at characteristic temperatures, Tn, that increase with x. Interestingly, the Yb(Pr)-123 sample with Pr content (x = 0.6) near x c reveals several anomalous features like transition from metallic to semiconducting-like ρ(T), an excessive broadening of the diamagnetic transition and weakening of the M(T) signal related to antiferromagnetic ordering of Pr ions. These observations can be consistently interpreted by assuming the presence of dynamically fluctuating striped phase in these systems.

Superconducting Properties of Te-Substituted (Tl2-xTex) Ba2CaCu2O8-δ

2019 ◽  
Vol 290 ◽  
pp. 239-244 ◽  
Author(s):  
Syahrul Humaidi ◽  
Eddy Marlianto ◽  
S. Marhaposan ◽  
Roslan Abd-Shukor
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Normal State ◽  
Electrical Resistance ◽  
High Temperature Superconductors ◽  
Solid State Reaction Method ◽  
Precursor Powder ◽  
Superconducting Properties ◽  
State Behavior ◽  
Reaction Method

The Tl2-xTexBa2CaCu2O8-δ (Tl-2212) high temperature superconductors with x = 0.0-0.5 have been prepared by the standard solid-state reaction method. The precursor powder were sintered at 900°C for 24 h with several grindings and heating. The powder were then pressed into pellets and heated at 910°C in oxygen flow for 4 min followed by furnace cooling. The electrical resistance versus temperature dependence measurements showed metallic normal state behavior for all samples. Substitution of Te at the Tl-site led to multi-phasic samples. The x = 0.4 sample showed the highestTc zero= 98 K and Tconset= 111K. The Tl-2212 phase increased from 50% for x=0 up to 92% in the x= 0.4 sample.

EFFECT OF SUBSTITUTION OF Na, Cd, Bi for Ca in Bi-Sr-Ca-Cu OXIDE SUPERCONDUCTORS

1989 ◽  
Vol 03 (12) ◽  
pp. 939-944 ◽  
Author(s):  
YU MEI ◽  
S.M. GREEN ◽  
C. JIANG ◽  
H.L. LUO ◽  
C. POLITIS
Keyword(s):  
Solid State ◽  
Normal State ◽  
Solid State Reaction ◽  
Oxide Superconductors ◽  
X Ray Diffraction ◽  
Normal State Resistivity ◽  
X Ray

Samples with compositions Bi 1.8 Pb 0.2 Sr 2( Ca 2−x Na x) Cu 3 O y, BiSr(Ca 1−x Cd x) Cu 2 O y and BiSr ( Ca 1−x Bi x) Cu 2 O y were prepared through solid state reaction. The X-ray diffraction results were analyzed and their resistivity behavior was studied. In general, all such substitution adversely affected their superconductive properties. All samples are of multiphase. The normal state resistivity behaves quite differently with the substitution of electropositive Na as compared with the replacement of electronegative Bi.

scholarly journals Preparation and study the structure of pure and impure barium titanate with Mg2+ ion

2018 ◽  
Vol 16 (37) ◽  
pp. 190-198
Author(s):  
Wasan Abd Alsatar Hekmt
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Barium Titanate ◽  
Solid State Reaction ◽  
Lattice Parameters ◽  
Magnesium Ion ◽  
Solid State Reaction Technique ◽  
Molar Ratios ◽  
Two Temperatures ◽  
Doped Barium Titanate

Pure and doped barium titanate with Mg2+ ion at two molar ratios x= (5%, 10%) mol. has been synthesized by solid state reaction technique. The powders sintered at two temperatures (1000 °C and 1400 °C). An XRD technique was used in order to study the crystal structure of pure and doped barium titanate, which confirmed the formation of the tetragonal phase of BaTiO3, and then calculate the lattice parameters of pure and doped barium titanate, the addition of magnesium ion Mg2+ can lead to decreases lattice parameters.

The Channel Structure of Mn0.86In0.12Ga2S4

2008 ◽  
Vol 63 (9) ◽  
pp. 1131-1134 ◽  
Author(s):  
Hartmut Haeuseler ◽  
Michael Wagener ◽  
Junyu Zhang
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Cross Section ◽  
Solid State Reaction ◽  
Channel Structure ◽  
Space Group

By solid state reaction of the binary sulfides, a new compound, Mn0.86In0.12Ga2S4, has been synthesized and its crystal structure determined. The compound crystallizes in the space group C2/m (no. 12) with a = 1232.6(2), b = 2636.9(5), c = 642.4(1) pm, β = 100.66(3)°, Z = 14. In the structure empty channels with a cross section of 320× 1082 pm2 running parallel to [001] are present.

STRUCTURAL AND SUPERCONDUCTING PROPERTIES OF Bi2Sr2Ca1−xPrxCu2Oy

1994 ◽  
Vol 08 (17) ◽  
pp. 2283-2292 ◽  
Author(s):  
D. RAMA SITA ◽  
R. SINGH
Keyword(s):  
Normal State ◽  
Conduction Mechanism ◽  
Lattice Parameter ◽  
Linear Increase ◽  
Variable Range Hopping ◽  
Superconducting Properties ◽  
Normal State Resistivity ◽  
Metal Insulator ◽  
Resistivity Measurements ◽  
Definite Correlation

Solid solutions of Bi 2 Sr 2 Ca 1−x Pr x Cu 2 O y (0 ≤ x ≤ 0.6) have been synthesized. The crystal structure and superconducting properties of the samples were examined by XRD and dc electrical resistivity measurements. Linear increase in normal state resistivity is observed with increasing Pr-content (x) for 0 ≤ x ≤ 0.55. Decrease in T c is observed with increasing x and metal–insulator transition is observed around x = 0.55. Although increase in normal state resistivity leads to decrease in T c value, we do not find any definite correlation between these parameters. The conduction mechanism in the semi-conducting sample is found to be Variable Range Hopping. From the decrease of c lattice parameter the possibility of existence of Pr ions in +4 state besides +3 state is inferred.

Transport Properties of Ru1Sr2Gd2-xCexCu2O10 Compounds

2013 ◽  
Vol 665 ◽  
pp. 347-352
Author(s):  
A. Roy ◽  
T.A. Jamadar ◽  
Ajay Kumar Ghosh
Keyword(s):  
Transport Properties ◽  
Normal State ◽  
Scanning Electron Micrographs ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Normal State Resistivity ◽  
X Ray ◽  
Annealing Conditions ◽  
Flowing Oxygen ◽  
Scanning Electron

We have synthesized Ru1Sr2Gd2-xCexCu2O10 (Ru-1222) materials using several concentrations of Ce. All ruthenocuprate compounds have been characterised by using standard X-ray diffraction (XRD) and Scanning Electron Micrographs (SEM). The concentration of Ce affects transport properties drastically. Compounds with x=0.5 remain nonsuperconducting with moderate resistivity even after annealing in different conditions. Enormous change in the normal state resistivity has been observed in different annealing conditions of Ru-1222 with x=0.5. Superconducting properties have been observed in compounds with x=0.65. The highest critical temperature obtained is 27.5K for x=0.65. In addition, the duration of annealing in flowing oxygen is found to be effective in changing the normal state resistivity for x=0.65.

scholarly journals Preparation and study the structure of pure and impure barium titanate with Mg2+ ion

2018 ◽  
Vol 16 (37) ◽  
pp. 178-189
Author(s):  
Wasan Abd Alsatar Hekmt
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Barium Titanate ◽  
Solid State Reaction ◽  
Lattice Parameters ◽  
Magnesium Ion ◽  
Solid State Reaction Technique ◽  
Molar Ratios ◽  
Two Temperatures ◽  
Doped Barium Titanate

Pure and doped barium titanate with Mg2+ ion at two molar ratios x= (5%, 10%) mol. has been synthesized by solid state reaction technique. The powders sintered at two temperatures (1000 °C and 1400 °C). An XRD technique was used in order to study the crystal structure of pure and doped barium titanate, which confirmed the formation of the tetragonal phase of BaTiO3, and then calculate the lattice parameters of pure and doped barium titanate, the addition of magnesium ion Mg2+ can lead to decreases lattice parameters.

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