مقاومت الکتریکی حالت عادی ابررساناهای Y(Nd)-123 با آلایشهای CaTh و La بر اساس مدل جفت‌پلارونی

Polycrystalline samples of Y1-2xCaxThxBa2Cu3O7-δ (with 0.00 ≤x ≤ 0.075) and NdBa2-xLaxCu3O7-δ (with 0.0≤x≤ 0.30) were prepared by the standard solid state method. The transport and superconducting properties have been studied by the resistivity measurements as a function of temperature and doping concentration. Data of resistivity as a function of temperature was analyzed in terms of the bipolaran model. The model well described resistivity data up to near the critical temperature. Obtained results suggested that the hole localization is the main reason for superconducting suppression in the charge neutral doped cuprates and the La doped Nd-123 in addition charge filling.