Principle

STM is one of the most typical and important SPM instruments for scanning and imaging sample surface at micro/nano-meter scale.

The principle of STM is based on the tunneling effect and tunneling current between probe (tip) and sample. When a tip approaches a sample with a certain bias to a very short distance S, such as several nanometers or even smaller, a tunneling current It occurs between them. According to the tunnel effect theory of quantum mechanics, there exists a negative exponential relationship between It and S, and thus the distance S can be accurately determined by detecting the tunneling current It. As the tip laterally scans over the sample, the 3D micro/nano-morphology of the sample surface can be then obtained.

Feature

Specially-designed horizontal STM probe unit

SEK-8501 STM owns a specially-designed horizontal STM probe, which is able to reduce the center of gravity and eliminates the vertical creeps of coarse and fine adjustment mechanisms; Equipped with USB-based optical microscopic monitoring system, it is capable of realizing the visualization of tip-sample operation and approaching process, so as to better satisfy the operating requirements of the users. In these ways, The novel STM and its probe unit is of more stability and superior performances.

Stabilized tri-axial piezoelectric scanner

It utilizes a stabilized tri-axial piezoelectric scanner which is able to eliminate the coupling of X, Y and Z piezoelectric elements between each other, as to avoid the image distortion. The scanner ensures better scanning linearity and independence, higher intensity and rigidity, as well as stronger driving force. Therefore, the scanner as well as the STM instrument is more suitable for scanning small and/or large, light and/or heavy samples.

Optimized scanning and feedback controlling system

With optimized scanning and feedback controlling system and multi-channel high-precision A/D & D/A interfaces, the STM owns higher scanning and imaging resolution, better repeatability and enhanced image quality.

Perfect software interfaces and functions

Powerful, friendly interface, can be applied to operating systems such as Windows XP / Win7 / Win8 / Win10. General operators can easily and skillfully master, and all operations from image scanning to image processing and data information calculation can be completed with just a mouse click. The local scanning area can be arbitrarily selected with the mouse to achieve image translation, positioning and zooming; the number of scans can be set and the scanning stop can be automatically controlled; it has the functions of surface scanning and line scanning in the X and Y directions; nano-scale three-dimensional sample surface can be obtained Morphology structure and section line; high-quality color / black and white flat image display and three-dimensional stereoscopic image display; with two-dimensional and three-dimensional nanoscale labeling function and particle size measurement function; with statistics and calculation of nano-level surface micro-roughness Function; can accurately measure the height and depth of micro-nano steps on the surface of the sample; perfect image processing functions, including cropping, pasting, rotation, contrast adjustment, brightness adjustment, color adjustment, background color adjustment, image smoothing, filtering, etc.

Simple and convenient instrument operation

The operation of this STM is quite simple and convenient so that any ordinary user and learner can carry out the operation, while no professional and skilled staff is demanded. Each process of probe tip installation, sample installation, coarse and fine approaching, image scanning, image acquisition and other operations can be completed within 1 minute for each. Therefore, It is much more suitable for scientific research, teaching experiments and product testing.

High stability and better anti-disturbance/interference performances

The STM can work perfectly under both good and common experimental conditions. It is capable of scanning samples and obtaining satisfactory images in general laboratories and rooms, on ordinary desks or tables, and under environments with slight vibration, disturbance and interference, etc. In other words, it is of better stability, better anti-disturbance capability, stronger anti-(optical, electric, electronic, and magnetic, etc.) interference performances, and faster scanning speed (up to 1 image/10 seconds).

High applicability in a wide range of applications

The STM can be widely applied in scientific research, undergraduate and graduate teaching experiments and nano-products testing.

It is suitable for scanning and imaging various materials such as metals, conductors, semiconductors, magnets and non-magnets, etc, while no special requirement of sample preparation is demanded.

Experiments and data

Some sample images scanned using the STM

Part list