Design of a simple and compact scanning tunneling microscope

Abstract

A simple and compact scanning tunneling microscope (STM) for operation in air is described. The design of the STM unit is based on the inertial sliding systems described in the literature, with sonic modifications to improve the stability of the scan unit. The STM is built of two concentric piezo electric tubes, the inner one for scanning the tip and the outer one for moving the sample holder towards or away from the tip. The vibration isolation system, mechanical construction of the scan unit, probe tip preparation, analogue and computer control electronics have all been described in this article. An analogue feedback system has been used for the constant current imaging. Images of highly oriented pyrolytic graphite have been obtained in air both on constant current and constant height modes of operation. The atomic resolution images obtained show lattice hexagonal lattice of graphite clearly.