Effects of surface miscuts on the epitaxy ofYBa2Cu3O7−δandNdBa2Cu3O7−γonSrTiO3(001)

We report on the effects of small miscuts of the (001) SrTiO 3 (STO) substrate surface, on the microstructure of epitaxial films of YBa 2 Cu 3 O 7 - δ and NdBa 2 Cu 3 O 7 - γ (NBCO). The most noticeable result is that, by growing NBCO films on miscut STO substrates with the steps intentionally oriented along a direction within 15° of [110], one reliably obtains NBCO films with a single [110] twinning variant (the [110] is completely eliminated), which is a precious characteristic for all applications involving flux flow.