TEMPERATURE DEPENDENCE OF THE COMPLEX MAGNETIC SUSCEPTIBILITY FOR THE OXIDIC Y1-xZrxBa2Cu3O7-δ SUPERCONDUCTORS

The thermal variation of the complex magnetic susceptibility χ(T) = χ′ (T) + iχ″ (T) for the oxidic superconducting compounds Y1-xZrxBa2Cu3O7-δ, x = 0.01, 0.05 and 0.10 was investigated. The real part of the complex magnetic susceptibility χ′ (T) below critical temperature Tc (χ) is negative and is lost in two stages when the temperature decreases. The inflexion point on the χ′ (T) curve corresponds to the two peaks on the temperature dependence of the imaginary part, χ″ (T), of the complex magnetic susceptibility and represents the critical temperatures for the intergranular superconductivity , i = 1, 2, 3 and for the intragranular superconductivity , i = 1, 2, 3. The concentration dependence of the critical temperatures is almost linear for the investigated compounds Y1-xZrxBa2Cu3O7-δ, x = 0.01, 0.05 and 0.10. The presence of the second weak peak or its absence on the χ″ (T) curves at characterizes an intense intergranular coupling.