Design and performance of a high-temperature, high-speed scanning tunneling microscope

This article describes the design and performance of a new scanning tunneling microscope (STM) which operates at elevated temperatures and high scanning speeds. To minimize the thermal displacements within the STM, a symmetric configuration was chosen with a large temperature gradient between the sample and the piezoelectric scanner. The thermal behavior of the STM was optimized further by means of a finite element analysis. The high scan rates (10⁵ data points/s) are accomplished with fast analogue electronics and a combination of a workstation and three transputers. The STM has imaged surfaces with atomic resolution between room temperature and 750 K, with low residual drifts only two hours after a major temperature change. The sample surface remains within the vertical range of the piezo actuator over a temperature interval of 159 K.