Flux pinning and phase diagrams in amorphous Ta0.3Ge0.7/Ge multilayers with coplanar defects - art. no. 184502

We report dc conductance measurements in the mixed state on two similar Ta0 .3Ge0.7/Ge superconducting multilayers with distinct differences in their i ntrinsic columnar microstructure. We measured flux flow activation energies and mapped the dynamic vortex phase diagram for magnetic fields aligned al ong and at large angles to the columnar microstructure. The data conform we ll with models on entangled vortex liquids and freezing into a strongly pin ned glass phase at the field dependent,melting temperature; The multilayer with the more pronounced columnar structure shows strongly enhanced flux pi nning for fields both along and at large angles to the columns.