Magnetic field dependence of the optimal BaZrO₃concentration in nanostructured YBa₂Cu₃O_7−δfilms

Abstract

The resistivity of YBa2Cu3O7−δ (YBCO) films deposited by a pulsed laser from nanograined targets doped with various amounts of BaZrO3 (BZO) is investigated in the thermally activated flux-flow (TAFF) regime, where the activation energy, U, has a linear temperature dependence. It is found that the magnetic field dependence of the irreversibility temperature, Tirr(B), has a maximum at some optimal BZO concentration, which depends on the applied magnetic field. Our results show that the superconducting materials used in different magnetic fields need optimization of the dopant concentration to achieve the best properties for various applications.

Influence of BaZrO3 dopant concentration on properties of YBa2Cu3O6+x films in magnetic fields up to 30 T

“…2͒ and on the other hand using resistivity results obtained at 65 K in higher magnetic field range above 15 T ͑Fig. 12 However, the n opt curve found in this work lies roughly 1 wt % higher than in measurements made in the TAFF regime. The BZO concentration that gives the maximum j c in the certain field n opt is calculated from the parabolic fit to j c ͑n͒ that gives an approximation of the data trend ͑inset of Fig.…”

“…The BZO concentration that gives the maximum j c in the certain field n opt is calculated from the parabolic fit to j c ͑n͒ that gives an approximation of the data trend ͑inset of Fig. 12 If the diameter of the columnar defect increases with BZO additions, as predicted in Ref. The error bars in n opt data are also estimated from the fits.…”

Hall effect and pinning regimes in YBa2Cu3O6+xСафончик1, Traito2, Tuominen3 et al. 2009Physica C: Superconductivity and its Applications3000View full textAdd to dashboardCite

“…The behaviour of T min ðBÞ can be explained by decrease of the irreversibility temperature T irr in magnetic field. The slope of the curve T min ðBÞ is similar to that of T irr ðBÞ [32]. In the investigated doping range the position of T min =T c does not depend on the BZO concentration, as observed also in irradiated YBCO single crystals [14].…”

“…1, the value of q xx from Ref. [32] and plot the Hall conductivity as a function of temperature and doping concentration, for an example in Fig. 3 are shown the data at B ¼ 3 T. The results show a general trend of the temperature dependence of Hall conductivity in low magnetic fields, where the superconducting state is realized.…”

Artificial pinning center technology to enhance vortex pinning in YBCO coated conductors

“…However, when the BZO doped YBCO target was used in the PLD method [14], it was confirmed by Goyal et al [63] and Yamada et al [64] that self-aligned BZO nanorods of 5-10 nm in the diameter were formed in a very dense state in the epitaxial YBCO films, as represented in figure 5. The nanorods are elongated and parallel to the c-axis of the films and they act as c-axis correlated pinning centers [65][66][67][68][69][70][71][72][73]. By BZO doping, J c reaches 0.5-0.7 MA cm −2 (77 K, 1 T, B c) and 0.1-0.2 MA cm −2 (77 K, 5 T, B c), which corresponds to a severalfold J c of those of epitaxial YBCO films.…”