Inter-grain coupling of granular MgB₂ superconductor in an applied AC magnetic field

Authors

Margie P. Olbinado ⋅ PH National Institute of Physics, University of the Philippines Diliman
Roland V. Sarmago ⋅ PH National Institute of Physics, University of the Philippines Diliman

Abstract

Inter-grain coupling in granular MgB₂ was investigated via AC magnetic susceptibility χ(T) measurements and simulations. The resistance R(T) encountered by currents flowing in between grains which determines the behavior of χ(T) was deduced. It was shown that R(T) is dependent on inter-grain tunneling conductance G(T) that characterizes quasi-particle tunneling, and the critical current i(T) of the Josephson tunnel junction in between grains.
Using a phenomenological model for AC loss generation in granular superconductors for low magnetic fields and the deduced inter-grain resistance R(T) components of the χ(T) were simulated.
The results suggest that as the applied field amplitude is increased, Josephson tunneling is suppressed which allows for more quasi-particle tunneling. The self-inductance is also decreased which indicates that there is less number of grains that can couple with increased magnetic field amplitude.

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Issue

2007: Proceedings of the 25th Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP-2007-3D-02

Section

Condensed Matter Physics

Published

2007-10-24

How to Cite

[1]

MP Olbinado and RV Sarmago, Inter-grain coupling of granular MgB2 superconductor in an applied AC magnetic field, Proceedings of the Samahang Pisika ng Pilipinas 25, SPP-2007-3D-02 (2007). URL: https://proceedings.spp-online.org/article/view/SPP-2007-3D-02.