Microwave absorption study of pinning regimes in $\bf Ba(Fe_{1-x}Co_x)_2As_2$ single crystals
| Autor: | Talanov, Yu., Beisengulov, N., Kornilov, G., Shaposhnikova, T., Vavilova, E., Nacke, C., Wurmehl, S., Panarina, N., Hess, C., Kataev, V., Büchner, B. |
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| Rok vydání: | 2012 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0953-2048/26/4/045015 |
| Popis: | Magnetic field dependent modulated microwave absorption (MMWA) measurements have been carried out to investigate vortex pinning effects in single crystals of the iron-based high-Tc superconductor Ba(Fe_{1-x}Co_x)_2As_2 with three different cobalt doping levels of x = 0.07, 0.09, and 0.11. The dependence of the MMWA hysteresis loops on temperature, magnetic field, and Co-concentration have been measured and analyzed using a theoretical model of microwave absorption in superconductors. The analysis reveals that in an underdoped crystal (x = 0.07) the so called \dtc-pinning due to magnetically ordered regions defines the temperature dependence of the critical current density, while in the optimally doped (x = 0.09) and overdoped (x = 0.11) samples the pinning is governed by structural imperfections due to inhomogeneous distribution of cobalt dopant and has the so called \delta-l character. Comment: 6 pages, 5 figures. Submitted to Phys. Rev. B |
| Databáze: | arXiv |
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