Fabrication of polycrystalline LaB6 tips array by femtosecond laser and its field emission performance

Abstract

Femtosecond laser processing technology has been used to achieve controlled processing of microtips array on the surface of polycrystalline LaB6 blocks. Under the condition of ensuring the integrity of the geometric morphology of the tips array, the tips with a height of 10 μm and a radius of curvature of 1 μm can be processed. The distribution of tips in the array is uniform, the morphology is complete, the crystal structure and physical phase of LaB6 have not changed after processing, which breaks through the technical problems of difficult processing and poor geometry consistency about polycrystalline rare-earth hexaboride tips emitter, and the processing area is no longer limited by the small size of single crystals. The field emission performance test indicated that the turn-on electric field is 2.8 V/μm, and the current density is 467.9 mA/cm2 when the applied electric field reached 9.4 V/μm.