Fluxon dynamics in Li–Al codoped by microwave surface resistance measurements
| Autor: | Marco Bonura, M. Monni, M. Li Vigni, A. Agliolo Gallitto |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Materials science
Fluxon Condensed matter physics Energy Engineering and Power Technology Field dependence Condensed Matter Physics Magnetic hysteresis Electronic Optical and Magnetic Materials Magnetic field Surface conductivity Hysteresis visual_art Lattice (order) visual_art.visual_art_medium Ceramic Electrical and Electronic Engineering |
| Zdroj: | Physica C: Superconductivity. 470:907-910 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/j.physc.2010.02.029 |
| Popis: | The magnetic-field-induced variations of the microwave surface resistance, R s , have been investigated in ceramic Mg1−x(LiAl)xB2, with x in the range 0.1 – 0.4 . The measurements have been performed on increasing and decreasing the DC magnetic field, H 0 , at fixed temperatures. At low temperatures, we have observed a magnetic hysteresis in the R s ( H 0 ) curves in all the investigated samples. On increasing the temperature, the range of H 0 in which the hysteretic behavior is visible shrinks; however, in the sample with x = 0.1 it is present up to temperatures close to T c . We show that the field dependence of R s can be quantitatively justified taking into account the critical-state effects on the fluxon lattice only in the sample with x = 0.4 . On the contrary, in the samples with x 0.4 the hysteresis exhibits an unusual shape, similar to that observed in others two-gap MgB2 samples, which cannot be justified in the framework of the critical-state models. |
| Databáze: | OpenAIRE |
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