The femtosecond laser micro-processing of the field-emission tip arrays in single crystal CeB6

The field-emission tip arrays (FEAs) in single crystal cerium-hexaboride (CeB6) were micro-processed by femtosecond laser. The results show that the femtosecond laser has no damage to the surface structure and phase of the CeB6 FEAs, and the FEA with the curvature radius of the optimal tips of about 0.6 mu m and the height of about 5 mu m have uniform morphology and the best field-emission performance. The single crystal CeB6 FEAs had good emission stability under the following conditions: the starting electric field of 2.8 V/mu m and an emission current density of 0.98 A/cm(2) at an electric field of 7.7 V/mu m. The calculations of material removal threshold and finite element simulation of the temperature field substantiate that laser peak energy density F-0 =0.95 J/cm(2) is in good agreement with the theoretical calculation result (0.51 J/cm(2) <= F-0 <= 2.12 J/cm(2)). Finally, the best process parameter range of this experiment is obtained. These results further indicating that the femtosecond laser micro-processing is an effective method to develop the vacuum field-emission application of single crystal CeB6.