High-resolution imaging in electron microscopy relies on an ultra-high vacuum environment on the order of 10⁻⁶ Pa, and the thermal stability of the diffusion pump oil is crucial for maintaining this environment. During operation, the oil pan must be continuously heated to 200°C-250°C to boil the pump oil, generating a high-speed oil vapor jet to remove gas molecules.
High-quality diffusion pump oil with stable thermal stability prevents decomposition and cracking at high temperatures, eliminating light component vapor contamination of the vacuum chamber and preventing heavy component coking and carbon buildup that clogs the nozzles. During electron microscopy imaging, even minute vacuum contamination or pressure fluctuations can lead to image blurring and reduced resolution. Thermally stable pump oil maintains extremely low vapor pressure over long periods, creating a clean environment for electron beam transmission and sample observation.
Furthermore, thermal stability extends the pump oil's lifespan, reducing instrument downtime caused by frequent oil changes. This ensures the continuity and accuracy of observing the microstructure of materials in scientific research and industrial testing, and is a key support for achieving nanometer-level observation precision in electron microscopy.