Proximity heater for elevated temperature in situ vacuum scanning tunneling microscopy of metal surfaces

Abstract

The design and application of a radiant heater assembly for elevated temperature scanning tunneling microscopy (STM) in ultrahigh vacuum (UHV) is presented. The proximity heater is a noninvasive modification to an existing commercial room-temperature microscope and is capable of radiatively heating samples up to 650 K in situ. Imaging at higher temperatures should be readily accessible with other microscope construction designs. It is demonstrated that this heater is well suited for enabling an STM to capture surface morphological transformations such as the motion of atomic steps on metal surfaces at elevated temperature. Various design issues and solutions related to variable temperature UHV-STM are also discussed. We believe the approach described to be general in nature, offering a direct route to adapting UHV-STM designs for elevated temperature imaging.