| 1. |
- Han, Shunhui, et al.
(författare)
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Fluctuation conductivity at high temperatures in polycrystalline Hg, Tl-1223 - Is there ID fluctuation behavior?
- 2004
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Ingår i: Physica. C, Superconductivity. - : Elsevier BV. - 0921-4534 .- 1873-2143. ; 408, s. 679-680
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Tidskriftsartikel (refereegranskat)abstract
- Detailed resistivity measurements were made for polycrystalline Hg1-xTlxBa2Ca2Cu3O8+delta (x = 0.2) in zero field and in the temperature region from zero resistance up to 300 K. The fluctuation conductivity Deltasigma was analyzed as a function of is an element of equivalent to In(T/Tc-mf) in the range -5.5 < Inc < -0.5. 1D behavior Of fluctuation conductivity was found at high temperatures (above the 2D regime) with a crossover temperature T-1*, above which the critical exponent was found to be -1.5.
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| 2. |
- Han, Shunhui, et al.
(författare)
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Study of the upper critical magnetic field HC2 of YBA2CU3O7-DELTA compounds
- 1992
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Ingår i: Solid State Communications. - 0038-1098 .- 1879-2766. ; 82:5, s. 379-380
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Tidskriftsartikel (refereegranskat)abstract
- Careful resistive measurements of the upper critical field H(c2) have been made on high quality polycrystalline YBa2Cu3O7-delta samples in magnetic fields up to 12 T. The data have been fitted on the form H(c2) infinity (T(c)-T)alpha to compare with theoretical models. A cusp is found in the H(c2) (T) curve for both of the samples. Different exponents-alpha are obtained depending on the temperature range used in the fitting procedure.
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| 3. |
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| 4. |
- Han, Shunhui, et al.
(författare)
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The upper critical-field of pb doped BI-SR-CA-CU-O compounds
- 1991
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Ingår i: Physica scripta. T. - : IOP Publishing. - 0281-1847 .- 0031-8949 .- 1402-4896. ; 44:11, s. 69-70
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Tidskriftsartikel (refereegranskat)abstract
- The upper critical field H(c2) of four Bi-(Pb)-Sr-Ca-Cu-O superconductors with the 110 K phase has been measured as a function of temperature. H(c2) exhibited a (T(c) - T)alpha-temperature dependence with alpha > 1 f two impure samples, but showed a linear temperature dependence for the purest sample, which is not expected according to current theories and other experiments.
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| 5. |
- Han, Shunhui, et al.
(författare)
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Thermodynamic fluctuation in doped BiSrCaCuO superconductors with 110K phase
- 1994
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Ingår i: Physica. B, Condensed matter. - : Elsevier BV. - 0921-4526 .- 1873-2135. ; 194-196, s. 1513-1514
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Tidskriftsartikel (refereegranskat)abstract
- The resistivity has been carefully measured for four sintered samples of Pb and Pb/Sb doped Bi-Sr-Ca-Cu-O superconductors with the 110 K phase from zero resistance temperature up to 300 K. The thermodynamical fluctuation have been fitted on the form DELTAsigma is-proportional-to epsilon(x) (epsilon=(T-T(c))/T(c)) in the regions -4 < In epsilon < -2. By choosing T(c) in different ways, it is shown that consistent results only could be obtained when T(c) is defined according to the Lawrence-Doniach theory.
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