Lal, Ratan (2010) A new method for estimating the critical current density of a superconductor from its hysteresis loop. Physica C: Superconductivity, 470 (4). pp. 281-284.

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Abstract

The critical current density Jc of some of the superconducting samples, calculated on the basis of the Bean’s model, shows negative curvature for low magnetic field with a downward bending near H = 0. To avoid this problem Kim’s expression of the critical current density, Jc = k/(H0 + H), where Jc has positive curvature for all H, has been employed by connecting the positive constants k and H0 with the features of the hysteresis loop of a superconductor. A relation between the full penetration field Hp and the magnetic field Hmin, at which the magnetization is minimum, is obtained from the Kim’s theory. Taking the value of Jc at H = Hp according to the actual loop width, as in the Bean’s theory, and at H = 0 according to an enhanced loop width due to the local internal field, values of k and H0 are obtained in terms of the magnetization values M+(−Hmin), M−(Hmin), M+(Hp) and M−(Hp). The resulting method of estimating Jc from the hysteresis loop turns out to be as simple as the Bean’s method.

Item Type:	Article
Subjects:	Applied Physics/Condensed Matter > Superconductivity Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	02 Jan 2012 07:49
Last Modified:	02 Jan 2012 07:49
URI:	http://npl.csircentral.net/id/eprint/7

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