Effect of point-like disorder on the vortex phase diagram in Bi2Sr2CaCu2O8-δ in oblique field

The phase diagram of vortex matter in the layered superconductor Bi2Sr2CaCu2O8-δ exposed to a magnetic field oblique to the crystalline c-axis contains two first order transition (FOT) lines . The first, HFOTm, separates the vortex solid from the vortex liquid, the second, HFOTct, separates the combined lattice state in the vortex solid from a tilted lattice state. The angular dependence of HFOTm in the tilted lattice region follows the anisotropic Ginzburg-Landau model , allowing for the determination of the anisotropy factor γeff and the contribution of magnetic coupling to the mutual interaction of 'pancake' vortices in the crossed lattice limit. The later parameter is directly related to the in-plane penetration depth λab. We investigate the evolution of the phase diagram of Bi2Sr2CaCu2O8-δ in oblique fields with point-like disorder, introduced by irradiation with 2.3 MeV electrons. Apart from the depression of Tc, point-like disorder induces an increase of γeff and a depression of the superfluid density.