In this study, triethylamine (TEA) dissolved in the methanol was used as a liquid nitrogen source to synthesize nitrogen-doped ultrananocrystalline diamond (N-UNCD) films on silicon substrates via microwave plasma enhanced chemical vapor deposition (MPCVD). High electrical conductivity and superior electron field emission (EFE) properties can be obtained for the N-UNCD films. By simply controlling the substrate temperature (T_S), the microstructure and electrical conductivity, as well as EFE properties of these N-UNCD films can be manipulated. The electrical conductivity of the N-UNCD films grown at T_S = 830 °C reaches 1174 S cm⁻¹ and they exhibit superior EFE properties with low turn-on field of 3.4 V μm⁻¹ and large EFE current density of 8.0 mA cm⁻² at an applied field of 6.2 V μm⁻¹. Further increasing the T_S to 890 °C, the obtained N-UNCD films possess higher electrical conductivity of 1854 S cm⁻¹ but show slightly degraded EFE properties. The possible underlying mechanism for the high conductivity and enhanced EFE properties have been discussed in detail, based on the characterization of morphological, phase, and chemical bonding features. The N-UNCD films with excellent electrical conductivity and superior EFE properties have great potential for application as electron emitters for flat panel displays and other vacuum microelectron devices.

The physical nature of the scratch behavior of CoCrFeMnNi HEA and its deformation mechanism at different morphology densities are investigated by molecular dynamics simulations. The results show that the groove morphology contributes to the reduction of surface plastic deformation and exhibits a friction-reducing effect. As the morphology density decreases, the surface deformation and atom pile-up decrease, and the plastic deformation in the scratch region decreases, resulting in a further enhancement of the friction reduction effect. The increase of scratch depth intensifies the plastic deformation of the specimens, and the average scratch coefficient of friction increases with the increase in scratch depth. The dominant plastic deformation mechanism in the scratch deformation of CoCrFeMnNi HEA with different morphology densities is the slip deformation of Shockley partial dislocations. The MD simulations are verified further by qualitatively comparing them with corresponding experimental observations of CoCrFeMnNi HEA.