Applications with a new low-temperature UHV STMat 5K

Abstract

A new dedicated UHV STM for investigations at T ≤ 5K is presented. To achieve such low temperatures and to ensure a high thermal stability, the low-temperature (LT) STM described here has a concentric system of bath cryostats. There are openings for tip and sample exchange at low T, and windows with an infrared radiation shield for optical access, which can both be closed by a door mechanism for LT-STM measurements. Efficient vibration isolation is realized by using spring suspension with eddy current damping. With the 3-d coarse positioning unit any region of interest within5mmby5mmon the sample is accessible even at 5K. For short turn-around cycles the sample and tip can both be exchanged at low temperatures. Atomically resolved images of Au.(111) at 5K in UHV demonstrate the excellent performance of this LT STM. As a typical application example the appearance of a charge-density wave on NbSe2, which occurs below a transition temperature of 33:5K, was imaged. © 1998 Springer-Verlag.