Effect of water adsorption on microscopic friction force on SrTiO3(001)

Abstract

A friction force microscope study in ultrahigh vacuum was conducted on an atomically flat SrTiO3(001) surface, where SrO and TiO2 domains were distinguished by the difference in friction force. It is revealed that the friction on the SrO became stronger with water adsorption relative to the TiO2 layer. The selective change in friction is attributed to the chemical reaction occurring on the SrO layer, which is supported by the results of x-ray photoelectron spectroscopy.