INVESTIGATION OF THE (001) CLEAVAGE PLANE OF POTASSIUM-BROMIDE WITH AN ATOMIC FORCE MICROSCOPE AT 4.2-K IN ULTRA-HIGH VACUUM

We have imaged the (001) surface of KBr with a UHV atomic force microscope at 4.2 K and 300 K. The sample was prepared by cleaving it in UHV along the (001) plane. We achieved atomic resolution at 4.2 K and resolved both the potassium and the bromium ions. We show atomically resolved images of flat terraces as large as 25 nm by 25 nm. Force-versus-distance measurements were taken, and the influence of the loading force acting between sample and cantilever on the appearance of friction effects and sample damage was studied.