The 3D XY model with random in-plane couplings is simulated to model the phase diagram of a disordered type II superconductor as a function of temperature T and randomness strength p for fixed applied magnetic field. As p increases to a critical p(c), the first order vortex lattice melting line turns parallel to the T axis, continuing down to low temperatures, rather than ending at a critical p...

A superconducting (SC) mixed state occurs in type-II superconductors where the upper critical field ${H}_{c2}$ is higher than thermodynamic ${H}_{c}$. When an applied between these fields, free energy depends weakly on order parameter which therefore can be small (SC state) or zero (normal at different parts of sample. In this paper we demonstrate how a normal along line traversing superconduct...

Neutrons have zero net electrical charge and can thus penetrate deeply into matter, but their intrinsic magnetic moment makes them highly sensitive to magnetic fields. These properties have been combined with radiographic (2D) and tomographic (3D) imaging methods to provide a unique technique to probe macroscopic magnetic phenomena both within and around bulk matter. Based on the spin-rotation ...

We review and analyze magnetization and specific heat investigations on type-II superconductors which uncover remarkable evidence for the magnetic field induced finite size effect and the associated 3D to 1D crossover which enhances thermal fluctuations. Indeed, the correlation length transverse to the magnetic field Hi, applied along the i-axis, cannot grow beyond the limiting magnetic length ...