We review some aspects of the isotope effect (IE) in superconductors. Our focus is on the influence of factors not related to the pairing mechanism. After summarizing the main results obtained for conventional superconductors, we review the effect of magnetic impurities, the proximity effect and non-adiabaticity on the value of the isotope coefficient (IC). We discuss the isotope effect of Tc a...

067002-1 We have investigated the temperature dependence of the optical reflectivity on a femtosecond scale in a near optimally doped YBa2Cu3O7 superconductor. The combined study of the lattice and carrier dynamics at temperatures above Tc allows us to identify two crossover temperatures in the normal state, giving evidence for an inhomogeneity of the pseudogap regime. These crossovers exhibit ...

Angular dependent resistivity measurements of optimally doped YBa2Cu3O7 films in fields H pulsed to 50 T are presented. Up to the highest H, the vortex melting field Hm increases and vortex motion is reduced for H aligned with the correlated pinning centers along the main crystalline axes, otherwise 3D anisotropic scaling describes the vortex dynamics. For H parallel ab, the rapid increase in H...

We have used the Low-Temperature Laser Scanning Microscope (LTLSM) technique for a spatially resolved investigation of the microwave transport properties, nonlinearities, and material inhomogeneities in an operating coplanar waveguide YBa2Cu3O7−δ (YBCO) microwave resonator on a LaAlO3 (LAO) substrate. The influence of twin-domain blocks, in-plane rotated grains, and micro-cracks in the YBCO fil...

Polarization-dependent X-ray absorption spectra (XAS) on the O 1s edge has been measured on a highly in-plane aligned (1 0 0) a-axis YBa2Cu3O7 d (YBCO) thin films. The in-plane XAS, that is, the electric field E of the linearly polarized synchrotron light parallels to bor c-axes of YBCO films (Ekb or Ekc), were obtained in a normal-incidence alignment. Furthermore, the XAS for Eka was calculate...