High-resolution imaging of LaAlO₃(100)–(1 × 4) reconstructed surface using non-contact atomic force microscopy

High-spatial-resolution imaging of an insulating LaAlO₃ film is performed with non-contact atomic force microscopy. The LaAlO₃ film was grown homogeneously on a LaAlO₃ substrate using pulsed laser deposition, and it was imaged without breaking the vacuum. The sample preparation method for obtaining atomically flat surfaces suitable for atomic resolution imaging is presented. The LaAlO₃ surface shows a reconstruction with a (1 × 4) structure, which is consistent with low-energy electron diffraction results. We believe that the method presented in this manuscript is an important advancement in the fabrication of insulating thin films used for atomic-level devices.