Significant Reduction of the Microwave Surface Resistance of MgB2 Films by Surface Ion Milling

Abstract

The microwave surface resistance Rs of MgB2 films with the zero-resistance temperature of - 39 K was measured at 8.0 - 8.5 GHz. The MgB2 films were prepared by deposition of boron films on c-cut sapphire, followed by annealing in a vaporized magnesium environment. The Rs appeared significantly reduced by ion milling of the as-grown MgB2 film surface, with the observed Rs of ~ 0.8 mohm at 24 K for an ion-milled MgB2 film as small as 1/15 of the value for the corresponding as-grown MgB2 film. The reduced Rs of the ion-milled MgB2 films is attributed to the effects of the Mg-rich metallic layer existing at the surfaces of the as-grown MgB2 films.

3 pages, 4 figures

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• Strongly linked current flow in polycrystalline forms of the new superconductor MgB2
• Superconductivity in Dense $Mg{B}_2$ Wires
• MgB2 superconducting thin films with a transition temperature of 39 Kelvin
• Single crystal MgB2 with anisotropic superconducting properties
• High critical current densities in superconducting MgB2 thin films
• Microwave properties of superconducting $Mg{B}_2$

Cited by in corpus (12)

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• Subharmonic gap structures and Josephson effect in MgB2/Nb micro-constrictions
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• Effects of the Two- Gap Nature on the Microwave Conductivity of 39 K Polycrystalline MgB2 Films
• Recent developments in the characterization of superconducting films by microwaves
• The superconducting gap of \QTR{em}{in situ} $Mg{B}_2$ thin films by microwave surface impedance measurements
• Effects of Ion Milling on the Microwave Properties of MgB2 Films
• Microwave performance of high-density bulk MgB2
• Study of the microwave electrodynamic response of MgB2 thin films
• Inducing superconductivity in quantum anomalous Hall regime