Superconductive and normal-state transport properties of epitaxialYBa2(Cu1−

Effect of anisotropic impurity scattering in superconductors

“…The potential produced by a given sort of impurity (defect) may be considered unique since the impurities tend to selectively substitute at characteristic sites in the crystal. The Zn and Ni atoms occupy the in-plane Cu sites [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and the electron irradiation displaces the oxygen atoms from the CuO 2 planes. [19][20][21][22] Therefore on a short length scale of the order of magnitude of the lattice constant a given impurity dopant produces the same potential of the same orientation throughout the crystal.…”

“…A similar analysis of Ni substituted samples shows that the pair-breaking effect in the unitary limit is stronger than observed experimentally. For the sake of comparison we present Ni doped Y −123 compound data 12,14,15,18 and our theoretical curves for the resonant scattering in Fig. 9.…”

“…Several experiments probing the effect of impurities or lattice defects on superconductivity in the cuprates have been carried out in order to get more insight into the symmetry of the superconducting state. The most thoroughly studied defects are Zn and Ni substitutions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] on the planar Cu sites and irradiation induced oxygen vacancies [19][20][21][22] in the copper oxygen planes. Yet the results are difficult to explain within a standard Abrikosov-Gorkov type theory of impurity scattering 23 for the scenario of the d-wave superconductivity, which is predicted to be extremely suppressed by the impurities.…”

From colossal magnetoresistance to solar cells: An overview on 66 years of research into perovskites

“…Thin‐film samples, even epitaxial ones, are much better suited for obtaining high j c values due to their intrinsic defects, including a certain density of grain boundaries and several types of dislocations such as growth spirals . In addition, artificial, point‐like defects have been engineered including the examples of Zn‐ and Ni substitution on the copper sites in the CuO 2 planes , columnar defects by heavy‐ion irradiation , impurity (green) phase incorporation , and BaZrO 3 inclusions . The critical current densities achieved with epitaxial films are surprisingly high, up to the order of 10 8 A cm −2 , but this is more an advantage for chip‐like devices and does not solve the need for long‐distance low‐loss current transport.…”