کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1818781 | 1525756 | 2010 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Yttrium doped La1âxYxO0.9F0.1FeAs superconductors: Hall and thermopower studies
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موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
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چکیده انگلیسی
The effect of yttrium substitution at the lanthanum site on the superconducting properties of La1âxYxO0.9F0.1FeAs ('x' = 0, 0.10, 0.20, 0.30, 0.50 and 0.60) oxypnictides has been studied. Powder X-ray diffraction studies confirm single phases till x = 0.1 beyond which minor amount of Y2O3 is observed. The temperature dependence of resistivity measurements confirm the superconducting transition temperature (Tc) of 34.8 (±0.05) K and corresponding Meissner transition at 34.3 K in the 'x' = 0.3 composition which is higher than that reported for the parent phase (LaO0.9F0.1FeAs (Tc = 28 K)). Further increase in the concentration of yttrium leads to broadening and suppression of the superconducting transition. The value of Hc2 at zero temperature is estimated to be about 60.5 T. The Seebeck coefficient (S) shows a negative sign indicating that the major contribution to the conductivity is by electrons. The Hall coefficient (RH) also remains negative throughout the temperature range supporting the thermopower results. The lattice parameters (a and c) decreases and the charge-carrier density increases with yttrium doping.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica C: Superconductivity - Volume 470, Issues 11â12, 1 June 2010, Pages 511-515
Journal: Physica C: Superconductivity - Volume 470, Issues 11â12, 1 June 2010, Pages 511-515
نویسندگان
S.J. Singh, J. Prakash, S. Patnaik, A.K. Ganguli,