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Boron implantation with in-situ dynamic annealing is used to produce highly conductive sub-surface layers in type IIa (100) diamond plates for the search of a superconducting phase transition. Here we demonstrate that high-fluence MeV ionimplantation, at elevated temperatures avoids graphitization and can be used to achieve doping densities of 6 at.%. In order to quantify the diamond crystal damage associated with implantation Raman spectroscopy was performed, demonstrating high temperature annealing recovers the lattice. Additionally, low-temperature electronic transport measurements show evidence of charge carrier densities close to the metal-insulator-transition. After electronic characterization, secondary ion mass spectrometry was performed to map out the ion profile of the implanted plates. The analysis shows close agreement with the simulated ion-profile assuming scaling factors that take into account an average change in diamond density due to device fabrication. Finally, the data show that boron diffusion is negligible during the high temperature annealing process. a)

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The effect of a temperature gradient at the surface of a metal on the thermionic emission current is calculated. The calculation is motivated by current research in which metal surfaces are exposed to high-intensity optical maser beams with a consequent heating of the surface. A Sommerfeld free-electron model of a metal is used in which the temperature of the metal is allowed to be a function of position. A modified distribution function for the electrons is calculated using the Boltzmann transport equation from which the thermionic current is obtained. Approximations are made that limit the theory to small changes in the distribution function but the results are valid for realizable experimental conditions. It is shown in an example that for Q-switched laser intensities observable effects can be expected.

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