A Simple,Compact and Rigid Scanning Tunneling Microscope

We present a homebuilt scanning tunneling microscope(STM)which employs an inner-wall polished sapphire guiding tube as a rail for the scanner to form a short tip-sample mechanical loop.The scanner is mounted on a square rod which is housed in the guiding tube and held by a spring strip.The stiff sapphire guiding tube allows the STM body to be made in a simple,compact and rigid form.Also the material of sapphire improves the thermal stability of the STM for its good thermal conductivity.To demonstrate the performance of the STM,high quality atomic-resolution STM images of high oriented pyrolytic graphite were given.

Direct Observation of Transition Metal Dichalcogenides in Liquid with Scanning Tunneling Microscopy

We present atomic-resolution images of TiSe2,MoTe2 and TaS2 single crystals in liquid condition using our home-built scanning tunneling microscopy(STM).By facilely cleaving of single crystals in liquid,we were able to keep the fresh surface not oxidized within a few hours.Using the high-stable home-built STM,we have obtained atomic resolution images of TiSe2 accompanied with the single atom defects as well as the triangle defects in solution for the first time.Besides,the superstructure of MoTe2 and hexagonal chargedensity wave domain structure in nearly commensurate phase of TaS2 were also obtained at room temperature(295 K).Our results provide a more efficient method in investigating the lively surface of transition metal dichalcogenides.Besides,the high stable liquid-phase STM will support the further investigations in liquid-phase catalysis or electrochemistry.