Thermodynamics and critical current density in HTS superconductors and beyond

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• Jeff Tallon, Robinson Research Institute, Victoria University, New Zealand.
• Wednesday 25 June 2014, 11:15-12:15
• Mott Seminar Room (531), Cavendish Laboratory, Department of Physics.

If you have a question about this talk, please contact Helen Verrechia.

With an HTS manufacturing business* spun out from our fundamental and applied R&D programmes over the past 27 years, we are particularly conscious of the ongoing need to drive up the critical current density, Jc, and determine its fundamental limits. This talk examines the relationship between thermodynamics and Jc both in the presence and absence of external applied fields. These two limits result in quite different phenomenology. In the self-field limit (Hext = 0) we find that Jc is limited by fundamental parameters and this provides a means to directly measure the London penetration depth, (T), from Jc(T), along with the symmetry and magnitude of the order parameter. The ideas developed are confirmed by the effects of impurity substitution on Jc(T) which have a distinctive character due to the rapid suppression of superfluid density due to impurity scattering. The ideas are also confirmed by applying to 31 different superconducting systems, including s-wave and d-wave, type I and type II. By combining with in-field Jc data we can also extract both the magnitude and T-dependence of the order parameter.

This talk is part of the Quantum Matter Seminar series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room (531), Cavendish Laboratory, Department of Physics
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• Quantum Matter Seminar
• School of Physical Sciences
• Thin Film Magnetic Talks

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