Nanoscale Laterally Modulated Properties of Oxide Ultrathin Films by Substrate Termination Replica through Layer-by-Layer Growth

作者：Ocal Carmen^*; Bachelet Romain; Garzon Luis; Stengel Massimiliano; Sanchez Florencio; Fontcuberta Josep

来源：Chemistry of Materials, 2012, 24(21): 4177-4184.

DOI：10.1021/cm302444s

• oxide surfaces
• chemical terminations
• oxide interfaces
• Kelvin microscopy
• ferroelectric films
• epitaxy

Modulation of oxide properties in a direction perpendicular to surfaces can be easily achieved by advanced thin film deposition tools. In contrast, simultaneous nanoscale modulation of properties in directions perpendicular and parallel to surfaces, as required for building three-dimensional (3D) nanometric devices, has remained elusive. Though bottom-up approaches allow obtaining controlled lateral growth, these techniques fail to achieve long-range order or do not allow simultaneous modulation of properties in the perpendicular direction. Here, we show that, by exploiting a dual strategy based on the spontaneous surface restructuration of some perovskite substrates and the layer-by-layer growth of nanometric heteroepitaxial perovskite layers, surfaces with laterally modulated surface relief, chemical termination, electrostatic potential, and electrical conductance can be obtained. As illustrative examples, conducting ferromagnetic manganite La2/3Sr1/3MnO3 and ferroelectric BaTiO3 ultrathin films have been grown on (001)SrTiO3 and (001)(La0.18Sr0.82)(Al0.59Ti0.41)O-3 substrates with self-ordered chemical terminations..

• 出版日期2012-11-13