GPI STMs is a series of ultrahigh vacuum scanning tunneling microscopes, designed for in situ surface processes study with atomic resolution. The following principles are in a basis of a design of the device:

• It should work in a combination to standard methods of the surface analysis and preparation in ultrahigh vacuum
• The open access to a surface of a sample for influence by electrons, ions, photons, atoms and molecules should be provided while scanning.
• Control electronics, vacuum module, sample and tip transfer system, arrester, wiring and other support components should remain the same for any type of STM head, including variable temperature or spin-polarised STMs

GPI-300 is a room temperature ultrahigh vacuum scanning tunneling microscope. It can be used for study of any surface processes at room temperature in vivo. Areas of application:

• chemical and photochemical reactions, heterogeneous catalysis
• coating and epitaxy
• semiconductor technologies
• adsorption
• modification of a surface by ions, electrons and other particles
• nanotechnology, single-atom manipulations

GPI-300 was developed in General Physics Institute (GPI) of the Russian Academy of Sciences in 1994 and since that time it has been successfully employed in the Surface Phenomena Laboratory at GPI. The main objects of studies are the reaction of chlorination of metals and semiconductors, carbon nanotubes material and radiation defect behaviour on a surface of graphite.

The original STM design described in [K.N.Eltsov, A.N.Klimov, S.L.Priadrin, V.M.Shevlyuga, V.Yu.Yurov, Phys. Low-Dim. Struct. 7/8 (1996) 115] was taken as a basis for the commercial device GPI-300. The scanner consists of three piezo-ceramics tubes, fixed in one line on a surface of a massive copper platform. Every tube has four outside and one internal metal electrodes, that allows to carry out positioning of the free end of the tube in three coordinates X, Y, Z. The tip holder is mounted on the left piezo-tube, and the sample holder is fixed to a special quartz slider that lies on four sapphire balls on the top of two others tubes. The sample and tip transfer from a linear manipulator into the STM is carried out by the XYZ-manipulator. After positioning to a distance of 2-3 mm the tip and the sample could be easily closed in to a distance of a tunnel gap (5-10 A) by piezo-inertial movement realized by means of two piezo-tubes: quartz slider with a sample slips on sapphire balls. Direction and the speed of movement is adjusted by the special generator, controlled by a computer. Such a movement is in Z- and X- directions with speed up to 2 mm/min with accuracy of positioning up to 5 nm.

The platform with the scanner is suspended on long springs as the main step of vibroisolation system, the other step is small viton columns, separating suspending system and a case of the vacuum chamber. Electrical feed-throughs for input/output signals are mounted on DN40-CF flanges of the nipple. The control and signal wires, that pass separately through metal tubes of a support frame, are distributed on a circle of the bottom motionless ring and then, are connected to the scanner by springs. Samples and tips transfer occurs at an arrested position of the scanner on motionless support on the bottom ring. For this purpose the arresting system, including standard rotary feed-through (DN40-CF or DN16-CF) is used.