Температурная зависимость электросопротивления электронно-допированных купратов
Abstract—Experimental data on the temperature dependence of electrical resistivity are analyzed for electron-
doped Nd2–xCexCuO4–δ cuprates in a wide range of cerium concentrations 0.12 ≤ x ≤ 0.20. It is shown that, in a wide temperature range above the superconducting transition temperature, the electrical resistivity mainly exhibits quadratic temperature dependence and decreases sharply at concentrations of x ≥ 0.17. Theoretical analysis based on the microscopic t – J model for strongly correlated electrons shows that the quadratic temperature dependence of electrical resistivity is attributed to electron scattering by spin excitations. To describe these excitations, a model of antiferromagnetic (AFM) spin fluctuations in the paramagnetic phase is proposed; the intensity of these fluctuations depends on the AFM correlation length. The quadratic temperature dependence of electrical resistivity agrees well with experimental data.