Research of Influence of Different Preparation Parameters on Secondary Electron Emission of a Single Crystal Diamond with the Purpose of Microchannel Devices Development with High Quantum Efficiency

Possibility and advantages of use of a single crystal diamond (HPHT and CVD) as highly effective secondary emitter are shown in this paper. The maximum secondary electron emission (SEE) coefficient about 14 at working accelerating voltage is received (several times exceeds SE coefficient of used materials, such as silicon), lack of dependence on diamond type is shown, dependence on current of primary beam is revealed. The main goals of experiments were to establish optimal characteristic of primary beam (such as energy of primary beam and current) and sample preparation for achievement the maximum coefficient of secondary electron emission (SEE coefficient). Experimental data were analyzed and an optimum technique of preparation of a diamond samples surface for use as secondary emitters was developed. Taking into account outstanding diamond characteristics there is a possibility for creation unique and highly effective detectors and converters based on effect of SE

Weak superconductivity in the surface layer of a bulk single-crystal boron-doped diamond

We have grown and investigated bulk single-crystal heavily boron-doped diamonds possessing superconductivity with $T_{C}^{\mathrm{onset}} =1.7\text{--}3.5\ \text{K}$ . Only the surface layer with the thickness less than $1\ \mu \text{m}$ showed the degenerate semiconductor behavior with transition to the superconducting state, while the bulk of the crystal was a typical doped semiconductor. The morphology of the surface layer is dendritic polycrystalline with an average boron content of 2.5–2.9 at.%. The typical Josephson junction current-voltage characteristic was observed. The degenerate semiconductor-superconductor transition as in single-crystal high-temperature superconductors and the structural data analysis of the surface layer indicate the two-dimensional character of superconductivity, and the actual superconducting structure is a set of few-nanometer thick boron carbide layers embedded in a diamond structure