Control of BaZrO_3 nanorod alignment in YBa_2Cu_3O_(7-x) thin films by microstructural modulation

摘要

The alignment of BaZrO_3-nanorods (BZO-NRs) in YBa_2Cu_3O_(7-x) was studied using vicinal substrates to modulate the microstructure. As the vicinal angle was increased to 10°, the angular splay of BZO-NRs increased. Correspondingly, the vortex pinning along the c-axis increased slightly, a possible consequence of enhanced vortex entanglement. Up to 10°, an increasing density of planar defects was observed, while at ～20° an orthogonal reorientation of the BZO-NRs along the a-b planes occurs. This suggests that the modulated microstructure introduces a competing effect on the BZO-NR formation and alignment, and beyond a critical vicinal angle, c-axis alignment is no longer favorable for BZO-NRs.