Paramagnetic effect in YBaCuO grain boundary junctions

A detailed investigation of the magnetic response of YBaCuO grain boundary Josephson junctions has been carried out using both radio-frequency measurements and Scanning SQUID Microscopy. In a nominally zero-field-cooled regime we observed a paramagnetic response at low external fields for 45 degree asymmetric grain boundaries. We argue that the observed phenomenology results from the d-wave order parameter symmetry and depends on Andreev bound states.Comment: To be published in Phys. Rev.

The use of thermal initiator to make organic bulk heterojunction solar cells with a good percolation path

10.1063/1.2965468Applied Physics Letters934-APPL

Surface morphology and in-plane-epitaxy of SmBa₂Cu₃O₇_-δ films on SrTiO₃ (001) substrates studied by STM and grazing incidence x-ray diffraction

The surface morphology and in-plane epitaxy of thin films of SmBa2Cu3O7−δ (SmBCO) grown on SrTiO3 (001) substrates with various thicknesses have been investigated by scanning tunneling microscopy (STM) and grazing incidence x-ray diffraction (GIXRD). As revealed by GIXRD, SmBCO films as thick as 500 Å grow pseudomorphically on SrTiO3 (001) surfaces, in comparison with a maximum of 130 Å for YBCO. This is probably due to a better lattice match of SmBCO (εa=1.2%, εb=−0.5%) compared to YBCO (εa=2.0%, εb=0.7%) with the SrTiO3 substrate. Three different types of surface morphology were observed by STM with increasing film thickness h: a) 2D growth for h<hc1, b) columnar structures for hc1 <h<hc2, c) spiral growth for h>hc2. With GIXRD, a density modulation is observed in the films with a thickness below hc2. For thicker films above hc2, introduction of screw dislocations leads to spiral growth

Improvement in the hole collection of polymer solar cells by utilizing gold nanoparticle buffer layer

10.1016/j.cplett.2008.01.013Chemical Physics Letters4531-373-76CHPL

Characterization and in situ-fluorescence diagnostic of the deposition od YBa_2Cu_30_7-x thin films by pseudo-spark electron beam ablation

SIGLEITItal