Nanometer-scale epitaxial strain release in perovskite heterostructures using "SrAlOx" sliding buffer layers

作者：Sato H K^*; Mundy J A; Higuchi T; Hikita Y; Bell C; Muller D A; Hwang H Y

来源：Applied Physics Letters, 2011, 98(17): 171901.

DOI：10.1063/1.3583459

We demonstrate the strain release of LaAlO3 epitaxial films on SrTiO3 (001) by inserting ultrathin "SrAlOx" buffer layers. Although SrAlOx is not a perovskite, nor stable as a single phase in bulk, epitaxy stabilizes the perovskite structure up to a thickness of 2 unit cells (uc). At a critical thickness of 3 uc of SrAlOx, the interlayer acts as a sliding buffer layer, and abruptly relieves the lattice mismatch between the LaAlO3 film and the SrTiO3 substrate, while maintaining crystallinity. This technique may provide a general approach for strain relaxation of perovskite films far below the thermodynamic critical thickness.

• 出版日期2011-4-25