Controllable preparation of microtips array on (100) crystal plane of single‐crystal lanthanum hexaboride ceramic

Single‐crystal lanthanum hexaboride (LaB6) is a functional ceramic with a low work function, strong resistance to ion bombardment, reasonable conductivity, and low evaporation rate. This study explored the use of a femtosecond laser combined with electrochemical etching to prepare a microtips array on the (100) crystal plane of a single‐crystal LaB6 ceramic. The ablation threshold of single‐crystal LaB6, processed using a femtosecond laser, was studied in addition to the microstructure and field emission properties of the sample. The study results proved that selecting a peak laser fluence F0 of 9.9 J/cm2 could help avoid the thermal ablation of the microtips array. The phase, crystal structure, and elemental composition of the microtips array on the single‐crystal LaB6 were unchanged. The prepared microtips array of a field emitter had a curvature radius, height, and minimum spacing of 0.4, 8, and 20 μm, respectively. The field emission test results showed that the starting electric field strength and field‐emission current density were 2.45 V/μm and 2.07 A/cm2, respectively, when the applied electric field strength was 5.2 V/μm. In addition, the field enhancement factor was 1493, indicating an excellent field emission stability. This paper explored the use of a wavelength 515nm femtosecond laser combined with electrochemical etching to controllable prepare the microtips array on (100) crystal plane of single‐crystal lanthanum hexaboride ceramic. This paper provided strong proof for the feasibility of fabricating the single‐crystal LaB6 field emitter by femtosecond laser combined with electrochemical etching. Meanwhile, it laid a good foundation for applying single‐crystal LaB6 field emitters in vacuum electronics and the surface micro/nano processing of hard and brittle ceramic materials.