TY - JOUR
T1 - Critical current properties and microstructures in impurity-doped ErBa2Cu3Oy films
AU - Horii, S.
AU - Ichinose, A.
AU - Ichino, Y.
AU - Ozaki, T.
AU - Yoshida, Y.
AU - Matsumoto, K.
AU - Mukaida, Masashi
AU - Shimoyama, J.
AU - Kishio, K.
PY - 2007/10/1
Y1 - 2007/10/1
N2 - We report minute doping effects of cobalt on critical current properties and microstructures in ErBa2Cu3Oy (Er123)/SrTiO3 thin films. Although critical temperatures (Tc) for the Co0.5%-doped Er123 films decreased with substrate temperature (Ts), magnetic-field angular (θ) dependence of Jc for the films grown at lower Ts showed clear c-axis peaks. Also from a fact that defects along the c-axis direction were observed in their cross-sectional microstructures, the c-axis peaks were derived from existence of c-axis correlated vortex pinning centers. On the other hand, Tc is almost constant for the change in Ts for the Co0.1%-doped Er123 films. Remarkable c-axis peaks were not observed in Jc-θ curves and, however, Jc(H∥ab)/Jc(H∥c) was decreased compared with that of the pure Er123 films. Namely, minute doping of cobalt showed a reduction effect of electromagnetic anisotropy of the Er123 matrix within the Co-doping levels at which Tc was maintained in ∼90 K.
AB - We report minute doping effects of cobalt on critical current properties and microstructures in ErBa2Cu3Oy (Er123)/SrTiO3 thin films. Although critical temperatures (Tc) for the Co0.5%-doped Er123 films decreased with substrate temperature (Ts), magnetic-field angular (θ) dependence of Jc for the films grown at lower Ts showed clear c-axis peaks. Also from a fact that defects along the c-axis direction were observed in their cross-sectional microstructures, the c-axis peaks were derived from existence of c-axis correlated vortex pinning centers. On the other hand, Tc is almost constant for the change in Ts for the Co0.1%-doped Er123 films. Remarkable c-axis peaks were not observed in Jc-θ curves and, however, Jc(H∥ab)/Jc(H∥c) was decreased compared with that of the pure Er123 films. Namely, minute doping of cobalt showed a reduction effect of electromagnetic anisotropy of the Er123 matrix within the Co-doping levels at which Tc was maintained in ∼90 K.
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U2 - 10.1016/j.physc.2007.03.473
DO - 10.1016/j.physc.2007.03.473
M3 - Article
AN - SCOPUS:34548510617
SN - 0921-4534
VL - 463-465
SP - 922
EP - 926
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
IS - SUPPL.
ER -