Polycrystalline samples of the Pr doped Yb 1-x Pr x Ba 2 Cu 3 O 7-δ (i.e. Yb(Pr)-123) system for 0≤x≤1 have been investigated for resistivity ρ 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 (dρ/dT) cc (corresponding to the linear ρ(T) region) and residual resistivity ρ0. In particular, the observed difference of critical Pr concentration where superconductivity is destroyed (x c ) in Yb(Pr)-123 (x c ≈ 0.65) and Y(Pr)-123 (x c ≈ 0.55) matches with the difference in the value of Pr concentration where the ratio (dρ/dT) cc /ρ0 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, Tn, 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 ρ(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.
Zinc Nanoparticles at Intercrystallite Sites of (Cu0.5Tl0.5)Ba2Ca3Cu4O12−δSuperconductor
