scholarly journals Computational Intelligence Approach for Estimating Superconducting Transition Temperature of Disordered MgB2Superconductors Using Room Temperature Resistivity

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Taoreed O. Owolabi ◽  
Kabiru O. Akande ◽  
Sunday O. Olatunji

Doping and fabrication conditions bring about disorder in MgB2superconductor and further influence its room temperature resistivity as well as its superconducting transition temperature (TC). Existence of a model that directly estimatesTCof any doped MgB2superconductor from the room temperature resistivity would have immense significance since room temperature resistivity is easily measured using conventional resistivity measuring instrument and the experimental measurement ofTCwastes valuable resources and is confined to low temperature regime. This work develops a model, superconducting transition temperature estimator (STTE), that directly estimatesTCof disordered MgB2superconductors using room temperature resistivity as input to the model. STTE was developed through training and testing support vector regression (SVR) with ten experimental values of room temperature resistivity and their correspondingTCusing the best performance parameters obtained through test-set cross validation optimization technique. The developed STTE was used to estimateTCof different disordered MgB2superconductors and the obtained results show excellent agreement with the reported experimental data. STTE can therefore be incorporated into resistivity measuring instruments for quick and direct estimation ofTCof disordered MgB2superconductors with high degree of accuracy.

1987 ◽  
Vol 99 ◽  
Author(s):  
A. R. Moodenbaugh ◽  
Y. Xu ◽  
M. Suenaga

Superconductivity near 30 K in the La-Ba-Cu-O system, first observed by Bednorz and Müller [1], was soon found to be attributable to the K2NiF4-type (at room temperature) compound La(2-x)BxxCuO4 [2]. Substitution of Sr and Ca for Ba yielded superconducting systems, also with high superconducting transition temperature Tc. Replacement of La by Y led to the discovery of the 90 K superconductors.


1975 ◽  
Vol 30 (2) ◽  
pp. 250-255
Author(s):  
W. Kessel

Abstract Isotope Effect and Pressure Coefficient of the Superconducting Transition Temperature within the Eliashberg-Theory Starting from the observation that both the mass of the ions and their volume control the phonon frequencies by stretching the phonon spectrum, the change of the Eliashberg-equations of the theory of superconductivity regarding these stretchings is considered. General expressions for the isotopic exponent and the pressure coefficient of the transition temperature are derived in which only derivatives of the transition temperature with respect to the fundamental parameters of the theory are involved. A comparison with experimental values shows that lead is not the metal with the highest transition temperature possible under the simple metals.


1989 ◽  
Vol 03 (03) ◽  
pp. 409-413 ◽  
Author(s):  
SHU-YUAN LIN ◽  
LI LU ◽  
HONG-MIN DUAN ◽  
BEI-HAI MA ◽  
DIAN-LIN ZHANG

The thermopower of YBa 2 Cu 3 O 7−δ single crystals has been measured from 300 K down to superconducting transition temperature. Strong anisotropy was observed. While the thermopower along ab-plane slightly increased with decreasing temperature, reaching 5 ~ 8 μ V/K around 120 K, the thermopower along c-axis showed typical metallic behavior with room temperature value as large as ~ 30 μ V/K .


2011 ◽  
Vol 110-116 ◽  
pp. 310-314
Author(s):  
Raminder Gill ◽  
P. Singh

In the age of technology, with smaller and smaller electronic components being used in a growing number of applications, one pertinent application of mathematics and physics is the study of superconductivity. Superconductive materials are capable of conducting electricity without any resistance and were first discovered by Kamerlingh Onnes in 1911 in a compound He at 4.2 K in what was to prove to be one of the most significant scientific breakthroughs of the 20th Century. Superconductivity and Magnetism are mutually exclusive to each other but the coexistence of both the phenomena leads to very interesting research of superconductivity at room temperature. In this paper, we have studied the effect of ferromagnetic and antiferromagnetic interactions on the superconducting transition temperature.


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