Search

We investigated the oxidation of oxygen vacancies at the surface of anatase TiO2(001) using a supersonic seeded molecular beam (SSMB) of oxygen. The oxygen vacancies at the top surface and subsurface could be eliminated by the supply of oxygen using an SSMB. Oxygen vacancies are present on the surface of anatase TiO2(001) when it is untreated before transfer to a vacuum chamber. These vacancies, which are stable in the as-grown condition, could also be effectively eliminated by using the oxygen SSMB.

The structure of the rutile TiO2(110)-(1 × 2) reconstructed surface is a phase induced by oxygen reduction. There is ongoing debate about the (1 × 2) reconstruction, because it cannot be clarified whether the (1 × 2) structure is formed over a wide area or only locally using macroscopic analysis methods such as diffraction. We used non-contact atomic force microscopy, scanning tunneling microscopy, and low-energy electron diffraction at room temperature to characterize the surface. Ti2O3 rows appeared as bright spots in both NC-AFM and STM images observed in the same area. High-resolution NC-AFM images revealed that the rutile TiO2(110)-(1 × 2) reconstructed surface is composed of two domains with different types of asymmetric rows.

Atomic resolution imaging of a SrTiO3(100)-([Formula: see text])-R33.7° reconstructed surface using non-contact atomic force microscopy (NC-AFM) and its simultaneous measurement with scanning tunneling microscopy (STM) is presented. Simultaneous STM and NC-AFM imaging reveals three patterns of image contrast depending on the tip apex condition and the relationship between the SrTiO3(100)-([Formula: see text])-R33.7° surface reconstructed structure and the NC-AFM image contrast. The NC-AFM image contrast variation is deduced from the tip apex polarity on the basis of an analysis of two images with opposite contrast. This interpretation is consistent with the results of simultaneous imaging of the SrTiO3(100)-([Formula: see text])-R33.7° surface. Furthermore, the results and interpretation identified an OH group, which is one of the surface defects, and this adsorption site.

We investigated the oxidation of oxygen vacancies at the surface of anatase TiO

We have designed and developed a combined system of pulsed laser deposition (PLD) and non-contact atomic force microscopy (NC-AFM) for observations of insulator metal oxide surfaces. With this system, the long-period iterations of sputtering and annealing used in conventional methods for preparing a metal oxide film surface are not required. The performance of the combined system is demonstrated for the preparation and high-resolution NC-AFM imaging of atomically flat thin films of anatase TiO2(001) and LaAlO3(100).

Image patterns of anatase TiO

A method for the automated extraction of the short-range part of the probe-surface interaction from force spectroscopy curves is presented. Our algorithm consists of two stages: the first stage determines a boundary that separates the region where the short-range interaction is dominantly acting on the probe and a second stage that finds the parameters to fit the interaction over the long-range region. We applied this method to force spectroscopy maps acquired over the Si ( 111 ) - ( 7 × 7 ) surface and found, as a result, a faint pattern on the short-range interaction for one of the probes used in the experiments, which would have probably been obviated using human-supervised fitting strategies.

Surface structure switching between (1 × 1) and (1 × 2) of rutile TiO2(110) is presented with scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). On the (1 × 1) surface, (1 × 2) chains are brought and elongated to form the typical (1 × 2) surface structure with cross-link pattern by iterations of sputtering and annealing. Backward transition from (1 × 2) to (1 × 1) is realized by annealing under an oxygen partial pressure.

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.