STM Images of Atoms

STM operates via quantum tunneling current between a probe and conductive sample, yielding atomic vertical and lateral resolution. SEM, or scanning electron microscopy, uses focused electron beams to generate secondary and backscattered electron signals across wider scan areas. While SEM provides broad topographic context, STM specializes in atomic-scale surface lattice inspection and localized electronic density mapping.

The main difference lies in the operating mechanism. STM measures quantum mechanical tunneling current and strictly requires conductive or semiconductive samples. In contrast, atomic force microscopy detects interatomic forces between a cantilever tip and the surface, permitting topography measurements on both conductive and non-conductive insulating specimens across diverse environmental or fluid conditions.

The purpose of STM is to acquire atomic-scale visualization and electronic data from conductive surfaces. Scientists utilize STM to investigate atomic defect structures, single-molecule arrangements, 2D material properties, nanolithography patterns, and electrochemical surface potentials, providing critical insight into fundamental nanoscience, molecular electronics, and advanced battery material interfaces.

An STM image is a high-resolution map of electron tunneling current or tip height recorded as a sharp conductive probe scans across a conductive sample. Rather than capturing geometric topography alone, an STM image depicts local surface electronic states, allowing researchers to directly visualize atomic lattices and individual atomic vacancies on the sample surface.

STM achieves atomic-scale resolution by exploiting the exponential sensitivity of tunneling current to tip-sample separation. Operating with ultra-low noise mechanical loops and rigid scanner configurations, systems can maintain precise tip stability to achieve sub-angstrom lateral and 0.2 nm vertical resolution for detailed material characterization at the atomic scale.

Multipurpose systems support scanning tunneling microscopy alongside atomic force microscopy modes including Tapping Mode, MAC Mode for biological materials, and Liquid Imaging. Modular nose cones allow labs to transition between STM tunneling, force measurements, KPFM, EFM, MFM, and in-situ electrochemical analysis on a unified platform.