Transmission electron microscope (TEM) is a key analytical tool in the fields of materials science, nanotechnology and life sciences. Its core performance depends on the electron emission efficiency and stability of the electron gun. As the core material of the hot cathode electron source, the barium tungsten electrode significantly optimizes the imaging resolution and stability of TEM by reducing the work function and improving the electron emission ability.
The barium tungsten electrode is composed of a tungsten matrix and a barium compound, and has high melting point, low work function and resistance to chemical poisoning. The main functions of the barium tungsten electrode in the transmission electron microscope are as follows:
1. Core Components of the Electron Gun
The electron gun of the TEM emits hot electrons by heating the barium tungsten electrode to form a high-brightness and high-coherence electron beam. The low work function of the barium tungsten electrode significantly improves the brightness of the electron source, allowing the electron beam to be focused to a sub-angstrom probe size, which directly determines the resolution limit of the TEM.
2. High-Resolution Imaging Support
In TEM imaging, the stable electron beam provided by the barium tungsten electrode ensures high-precision characterization of crystal structure, nanoparticle morphology and interface defects. Its anti-chemical poisoning property avoids performance degradation under long-term operation and meets the needs of dynamic evolution observation of materials (such as phase change, oxidation process).
3. Adaptation of In-Situ Experimental Technology
Combined with in-situ heating, stretching or electrochemical devices, the TEM system supported by the barium tungsten electrode can monitor the behavior of materials under extreme conditions in real time. Its low-noise electron emission characteristics ensure the signal-to-noise ratio of in-situ experiments and promote the understanding of the intrinsic properties of materials.
4. Long Life and Maintenance Optimization
The reserve design of the barium tungsten electrode continuously replenishes barium atoms through the porous tungsten matrix, extending the electrode life and reducing the need for equipment downtime maintenance. This feature is particularly suitable for high-throughput TEM platforms that need to operate continuously.
