Practical vortex diodes from pinning enhanced YBa2Cu3O7-d (2009)
Harrington, S. A., MacManus-Driscoll, J. L., Durrell, J. H.
We identify a scalable, practical route to fabricating a superconducting diode. The device relies for its function on the barrier to flux vortex entry being reduced at the substrate interface of a...
Cross-over between channeling and pinning at twin boundaries in YBa2Cu3O7 thin films (2006)
Palau, A., Durrell, J. H., MacManus-Driscoll, J. L., Harrington, S., Puig, T., Sandiumenge, F., ...
The critical current (Jc) of highly twinned YBa2Cu3O7 films has been measured as a function of temperature, magnetic field and angle. For much of the parameter space we observe a strong suppression...
Strong Pinning Enhancement in MgB2 Using Very Small Dy2O3 Additions (2006)
Chen, S. K., Wei, M., MacManus-Driscoll, J. L.
0.5 to 5.0 wt.% Dy2O3 was in-situ reacted with Mg + B to form pinned MgB2. While Tc remained largely unchanged, Jc was strongly enhanced. The best sample (only 0.5 wt.% Dy2O3) had a Jc of 6.5 x 10^5...
Strong influence of boron precursor powder on the critical current density of MgB2 (2005)
Chen, S. K., Yates, K. A., Blamire, M. G., MacManus-Driscoll, J. L.
The influence of the nature of the boron precursor on the superconducting properties of polycrystalline MgB2 was studied. Critical current densities for the MgB2 made from high purity amorphous boron...
Benefits of current percolation in superconducting coated conductors (2005)
Rutter, N. A., Durrell, J. H., Blamire, M. G., MacManus-Driscoll, J. L., Wang, H., Foltyn, S. R.
The critical currents of MOD/RABiTS and PLD/IBAD coated conductors have been measured as a function of magnetic field orientation and compared to films grown on single crystal substrates. By varying...
Improved Current Densities in MgB2 By Liquid-Assisted Sintering (2005)
Chen, S. K., Lockman, Z., Wei, M., Glowacki, B. A., MacManus-Driscoll, J. L.
Polycrystalline MgB2 samples with GaN additions were prepared by reaction of Mg, B, and GaN powders. The presence of Ga leads to a low melting eutectic phase which allowed liquid phase sintering and...
Normal state properties of high angle grain boundaries in (Y,Ca)Ba2Cu3O7-delta (2004)
Mennema, S. H., Ransley, J. H. T., Burnell, G., MacManus-Driscoll, J. L., Tarte, E. J., Blamire, M. G.
By lithographically fabricating an optimised Wheatstone bridge geometry, we have been able to make accurate measurements of the resistance of grain boundaries in Y1-xCaxBa2Cu3O7-d between the...
MacManus-Driscoll, J. L., Foltyn, S. R., Jia, Q. X., Wang, H., Serquis, A., Civale, L., ...
There are numerous potential applications for superconducting tapes, based on YBa2Cu3O7-x (YBCO) films coated onto metallic substrates. A long established goal of more than 15 years has been to...
Enhancement of Critical Current Density in low level Al-doped MgB2 (2004)
Berenov, A., Serquis, A., Liao, X. Z., Zhu, Y. T., Peterson, D. E., Bugoslavsky, Y., ...
Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping...
Angular dependent vortex pinning mechanisms in YBCO coated conductors and thin films (2003)
Civale, L., Maiorov, B., Serquis, A., Willis, J. O., Coulter, J. Y., Wang, H., ...
We present a comparative study of the angular dependent critical current density in YBa2Cu3O7 films deposited on IBAD MgO and on single crystal MgO and SrTiO3 substrates. We identify three angular...
Lockman, Z., Qi, X., Berenov, A., Goldacker, W., Nast, R., Deboer, B., ...
Physica C, 383(2002) S.127-39
Lockman, Z., Berenov, A., Goldacker, W., Nast, R., Deboer, B., Holzapfel, B., ...
Journal of Materials Research, 18(2003) S.327-37
Study of the surface oxidation epitaxy of pure Ni. (2003)
Lockman, Z., Qi, X., Berenov, A., Goldacker, W., Nast, R., Deboer, B., ...
Chandra, T. [Hrsg.]
Effective Vortex Pinning in MgB2 thin films (2002)
Bugoslavsky, Y., Cowey, L., Tate, T. J., Perkins, G. K., Moore, J., Lockman, Z., ...
We discuss pinning properties of MgB2 thin films grown by pulsed-laser deposition (PLD) and by electron-beam (EB) evaporation. Two mechanisms are identified that contribute most effectively to the...
Lockman, Z., Goldacker, W., Nast, R., Deboer, B., MacManus-Driscoll, J.L.
Proc.of the 5th European Conf.on Applied Superconductivity (EUCAS 2001), Copenhagen, DK, August 26-30
The structure of the superconducting gap in MgB2 from point-contact spectroscopy (2001)
Bugoslavsky, Y., Miyoshi, Y., Perkins, G. K., Berenov, A. V., Lockman, Z., MacManus-Driscoll, J. L., ...
We have studied the structure of the superconducting gap in MgB2 thin films by means of point-contact spectroscopy using a gold tip. The films were produced by depositing pure boron on a sapphire...
Zhukov, A. A., Purnell, A., Miyoshi, Y., Bugoslavsky, Y., Lockman, Z., Berenov, A., ...
The microwave power, dc magnetic field, frequency and temperature dependence of the surface resistance of MgB2 films and powder samples were studied. Sample quality is relatively easy to identify by...
Zhukov, A. A., Cohen, L. F., Purnell, A., Bugoslavsky, Y., Berenov, A., MacManus-Driscoll, J. L., ...
In this paper we present the results of measurements of the microwave surface impedance of a powder sample and two films of MgB$_2$. One film has $T_c=30$ K and is not textured, the other is...
Berenov, A., Lockman, Z., Qi, X., Bugoslavsky, Y., Cohen, L. F., ...
MgB2 thin films were cold-grown on sapphire substrates by pulsed laser deposition (PLD), followed by post-annealing in mixed, reducing gas, Mg-rich, Zr gettered, environments. The films had Tcs in...