We present our recent results on the temperature dependence of current-voltage characteristics for polycrystalline Y1-xPrxBa2Cu3O7-δ superconductors with x = 0.0, 0.1 and 0.3. The experimental results are found to be reasonably well fitted for all samples by a power like law of the form V = R (I - Ic)a (T). Here, we assume that a (T) = 1 + Φ0 IC (T) / 2 π kB T and IC (T) = IC (0) (1 - T / TC)3 / 2 for the temperature dependences of the power exponent and critical current, respectively. According to the theoretical interpretation of the obtained results, nonlinear deviation of our current-voltage characteristics curves from Ohmic behavior (with a (TC) = 1) below TC is attributed to the manifestation of dissipation processes. They have a characteristic temperature Tp defined via the power exponent as a (Tp) = 2 and are related to the current induced depinning of Abrikosov vortices. Both TC (x) and Tp (x) are found to decrease with an increase of Pr concentration x reflecting deterioration of the superconducting properties of the doped samples.
|Número de páginas||4|
|Publicación||Physics Letters, Section A: General, Atomic and Solid State Physics|
|Estado||Publicada - 21 jul. 2008|