Intermodulation distortion and surface resistance in impurity-doped YBCO and MgB 2
| Autor: | Y.D. Agassi, Daniel E. Oates |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Doping Energy Engineering and Power Technology Condensed Matter Physics Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Impurity Meissner effect Condensed Matter::Superconductivity Magnesium diboride Electrical and Electronic Engineering Penetration depth Sheet resistance Intermodulation |
| Zdroj: | Physica C: Superconductivity and its Applications. 506:119-132 |
| ISSN: | 0921-4534 |
| Popis: | Calculations of the microwave intermodulation distortion (IMD) and surface resistance of impurity-doped YBCO, MgB 2 and Nb are presented. These are qualitatively distinct superconductors due to their energy-gap symmetries, d-wave (l = 2), i-wave (l = 6) and s-wave (l = 0), respectively. The calculations are compared with previously published IMD and surface-resistance measurements of impurity-doped YBCO and Nb. The agreement between the data and fitted calculations is excellent in all cases. In the absence of IMD and surface-resistance measurements for doped MgB 2 , we present representative predictions. The calculations are based on a Green’s-function approach that yields analytical expressions for the penetration depth and the nonlinear kernel in the constitutive relation. This penetration-depth expression reproduces the measured T 2 low-temperature variation for doped superconductors and the surface-resistance reduction over that of the pure material. Regarding the IMD in superconductors with a nodal energy gap, the effect of doping is to enhance its magnitude and suppress its low-temperature 1/ T 2 divergence predicted by the nonlinear Meissner effect. |
| Databáze: | OpenAIRE |
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