The Vortex Lattice of a Type II Superconductors Studied by Small Angle Neutron Scattering
نویسنده
چکیده
In this laboratory work we will study the vortex lattice VL of a type II superconductor using Small Angle Neutron Scattering SANS. The sample is a single crystal of Nb, a superconductor with a Tc = 9.3 K and lower and upper critical fields of μ0Hc1 = 0.18T and μ0Hc2 = 0.4T, respectively. For external magnetic fields between Hc1 and Hc2 the superconductor is in the so-called intermediate state. There, the magnetic field partially penetrates the material in the form of individual flux lines, forming a regular lattice, the ”vortex lattice” VL. This lattice can be directly probed using small angle neutron scattering SANS techniques. In this experiment we will study the behaviour of the VL as a function of the magnetic field.
منابع مشابه
Visualizing the morphology of vortex lattice domains in a bulk type-II superconductor
Alike materials in the solid state, the phase diagram of type-II superconductors exhibit crystalline, amorphous, liquid and spatially inhomogeneous phases. The multitude of different phases of vortex matter has thence proven to act as almost ideal model system for the study of both the underlying properties of superconductivity but also of general phenomena such as domain nucleation and morphol...
متن کاملSymposium on Neutron Scattering Studies of Vortex Structures in Superconductors J. Lynn, Chairman Neutron scattering studies of the vortex lattice in niobium and ‘8123 superconductors (invited)
The magnetic flux lattice undergoes a melting transition not only in high-T, oxide superconductors, but also in conventional superconductors, as recently observed in superconducting niobium films. Small-angle neutron scattering was used to investigate the properties of the magnetic flux lattice in a large, high-quality single crystal of niobium. The small London penetration depth of niobium giv...
متن کاملObservation of well-ordered metastable vortex lattice phases in superconducting MgB2 using small-angle neutron scattering.
The vortex lattice (VL) symmetry and orientation in clean type-II superconductors depends sensitively on the host material anisotropy, vortex density and temperature, frequently leading to rich phase diagrams. Typically, a well-ordered VL is taken to imply a ground-state configuration for the vortex-vortex interaction. Using neutron scattering we studied the VL in MgB(2) for a number of field-t...
متن کاملAn Interpretation of the Neutron Scattering Data on Flux Lattices of Superconductors
Small angle neutron diffraction experiments are analyzed using recently developed and properly generalized one-field effective free energy method. In the case of experiment of Keimer et al on YBCO, we show that the fourfold symmetry of the underlying crystal is explicitly broken, but the reflection with respect to the [110] and [11̄0] axes remains a symmetry. The vortex lattice also becomes gene...
متن کاملInvestigation of symmetry-breaking flux-line lattice phases in superconductors by small-angle neutron scattering
In single-crystal superconductors in the mixed state, flux-line structures may have a lower symmetry than the host crystal. In this case, multiple degenerate flux lattice domains may be present simultaneously and give rise to complicated small-angle diffraction patterns. The interpretation of these patterns in terms of the flux lattice structure in a single domain is discussed, with particular ...
متن کامل