Conductivity fluctuations of polycrystalline Ag-doped YBa2Cu3O7-δ superconductor
نویسندگان
چکیده
منابع مشابه
Measurement of the upper critical field of optimally-doped YBa2Cu3O7-δ in megagauss magnetic fields
We have observed crossover from superconducting state to normal state in optimally doped YBa2Cu3O7−δ (Tc ∼ 90 K) in very high magnetic fields (B) up to 600 T applied parallel to CuO2 planes (B⊥c). This is the first systematic critical field measurement at low temperatures in the geometry of the B‖CuO2-planes using superconductors with Tc greater than 90 K. In order to perform high-sensitivity m...
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We report a systematic investigation of dynamical fluctuation effects in the frequency-dependent microwave conductivity (45 MHz–45 GHz) of YBa2Cu3O72d thin films for T * Tc. Our measurements directly yield a dynamical critical exponent z in the range 2.3–3.0, and the fluctuation lifetime tfl, which diverges more quickly than Gaussian theory predicts as the temperature approaches Tc from above, ...
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Doping Mott insulators with charge causes dramatic changes in their physics. Spectacular results of the doping are superconductivity in cuprates and colossal magnetoresistivity in manganites. In all cases, doping is accompanied by mesoscopic phase separation that signalises that the magnetic short-range forces start to be competed by the long-range Coulomb force. The long range order is, theref...
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The in-plane normal-state resistivity of Zn-doped YBa2Cu3O7−δ and heavily underdoped pure YBCO single crystals is measured down to low temperatures under magnetic fields up to 18 T. We found that the temperature dependence of the normal-state ρab does not obey log(1/T ) and tends not to diverge in the low temperature limit. The result suggests that the “ground state” of the normal state of YBCO...
متن کاملFluctuations in the microwave conductivity of YBa2Cu3O7- delta single crystals in zero dc magnetic field.
We present a quantitative analysis of finite frequency fluctuation conductivity above and below Tc in cuprate superconductors in zero dc magnetic field. In a YBa2Cu3O72d crystal showing a linear in temperature increase of the penetration depth at low temperatures, we find that two-dimensional ~2D! finite frequency Gaussian conductivity fluctuations above Tc cross over into a slower divergence o...
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ژورنال
عنوان ژورنال: Brazilian Journal of Physics
سال: 2010
ISSN: 0103-9733
DOI: 10.1590/s0103-97332010000200012