A possible correlation between suppression of superconductivity, magnetic ordering and normal state resistivity parameters in the Yb1-xPrxBa2Cu3O7-delta system

摘要

Polycrystalline samples of the Pr doped Yb1-xPrxBa2Cu3O7-delta (i.e. Yb(Pr)-123) system for 0 less than or equal to x less than or equal to 1 have been investigated for resistivity rho and magnetization M as a function of temperature in normal and superconducting states. The gradual decrease in superconducting critical temperature T-c(x) is found to be correlated with the x-dependent ratio of resistivity slope (drho/dT)(cc) (corresponding to the linear rho(T) region) and residual resistivity rho(0). In particular, the observed difference of critical Pr concentration where superconductivity is destroyed (x(c)) in Yb(Pr)-123 (x(c) approximate to 0.65) and Y(Pr)-123 (x(c) approximate to 0.55) matches with the difference in the value of Pr concentration where the ratio (drho/dT)(cc)/rho(0) tends to go to zero in them. The M(T) data of the Yb(Pr)-123 samples show magnetic ordering for x > x(c) at characteristic temperatures, T-n, that increase with x. Interestingly, the Yb(Pr)-123 sample with Pr content (x = 0.6) near x(c) reveals several anomalous features like transition from metallic to semiconducting-like rho(T), an excessive broadening of the diamagnetic transition and weakening of the M(T) signal related to antiferromagnetic ordering of Pr ions. These observations can be consistently interpreted by assuming the presence of dynamically fluctuating striped phase in these systems. [References: 27]