Adaptix worked with NPL through the Analysis for Innovators (A4I) Programme, to understand how it could improve the materials of its cold cathode field emitters, and thereby improve performance.
Adaptix developed new materials and coatings which it hoped would improve the product and sent these to NPL to test and validate. NPL applied a wide range of state-of-the-art analysis tools to examine the structural and chemical properties of the material samples, including high resolution scanning electron microscopy (SEM) for structural analysis, and X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) for chemical analysis. Measurements were taken of the geometry of tips, quality of coatings, contaminants and oxidation state.
Research revealed differences between tip geometries and coating quality which potentially affected X-ray emission uniformity, identified surface chemistry contamination caused by manufacturing processes and highlighted the impact of high current on material degradation.
Through this research, Adaptix were able to improve uniformity by identifying optimal materials and coatings. It also helped them remove sources of contamination which they were not aware of – an issue that may have become a serious problem down the line. Additionally, measurements of how materials responded to different vacuum conditions allowed Adaptix to implement control mechanisms to limit failure, such as identifying the optimum vacuum levels. All of which improves the performance of the product.