Control of BaZrO3 nanorod alignment in YBa2Cu3O7−x thin films by microstructural modulation

The alignment of BaZrO3-nanorods (BZO-NRs) in YBa2Cu3O7−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.