Diamond

About: Diamond is a research topic. Over the lifetime, 56028 publications have been published within this topic receiving 925125 citations.

IBIC characterization of an ion-beam-micromachined multi-electrode diamond detector

Abstract: Deep Ion Beam Lithography (DIBL) has been used for the direct writing of buried graphitic regions in monocrystalline diamond with micrometric resolution. As part of the development and the characterization of a fully ion-beam-micromachined solid-state ionization chamber, a device with interdigitated electrodes was fabricated by using a 1.8 MeV He+ ion microbeam, which scanned a 40 μm thick homoepitaxial detector grade diamond sample grown by chemical vapor deposition (CVD). In order to evaluate the ionizing-radiation-detection performance of the device, charge collection efficiency (CCE) maps were extracted from Ion Beam Induced Charge (IBIC) measurements carried out by probing different arrangements of buried micro-electrodes. The analysis of the CCE maps allowed an exhaustive evaluation of the detector features, in particular the individuation of the different role played by electrons and holes in the formation of the induced charge pulses. Finally, a comparison of the performances of the detector with buried graphitic electrodes with those relevant to conventional metallic surface electrodes evidenced the formation of a dead layer overlying the buried electrodes as a result of the fabrication process.

Tribological behavior of HFCVD multilayer diamond film on silicon carbide

Abstract: A novel deposition method combining hot filament chemical vapor deposition (CVD) method is proposed, with which a multilayer diamond film consisting of three layers of microcrystalline diamond (MCD) film with the gradually decreasing grain size as the number of layers increase is fabricated on silicon carbide substrate. The tribological behavior is examined on a reciprocating ball-on-plate tribometer. Meanwhile, the silicon carbide and one-layer diamond film are also conducted for comparison. The experimental results show that the friction coefficients of the silicon carbide are 0.35 and 0.40 for dry sliding against tungsten carbide and silicon nitride counterfaces, respectively. The corresponding friction coefficients of the one-layer diamond film reduce to 0.30 and 0.14, and the multilayer diamond film for these two contacts reaches to the lowest friction coefficients of 0.28 and 0.07. Moreover, the multilayer diamond film not only presents the high wear resistance, but also greatly reduces the wear rate of its counterpart as compared with the one-layer diamond film. Hence, the multilayer diamond film can be regarded as an alternative and potential technique to improve the tribological behavior of diamond film.

Nucleation and Growth of Low-Pressure Diamond

Abstract: The great breakthrough in low-pressure diamond synthesis research came with the discovery that diamond growth is also possible on non-diamond substrates /1,2/. Since then these methods have developed rapidly /3–6/. Despite intensive work by hundreds of scientists, in-depth knowledge about the diamond nucleation and growth mechanism is still lacking. Several authors /7–12/ have discussed atomic attachment mechanisms, but more systematic experimental work and quantitative data which could provide practical guidance is still needed.

Development of micro-XANES mapping in the diamond anvil cell.

Abstract: Energy-dispersive X-ray absorption spectroscopy is now a well established method that has been applied to a broad range of applications. At the energy-dispersive EXAFS beamline of the ESRF, ID24, the recently achieved 5 × 5 µm focal spot combined with fast acquisition has allowed complex and non-uniform samples to be mapped and images to be obtained where each pixel contains full XAS information. This method has been applied to a study under extreme conditions of pressure and temperature in a diamond anvil cell in transmission mode. The case study was the investigation of the Fe K-edge XANES of (Mg,Fe)SiO3-perovskite and (Mg,Fe)O-ferropericlase on decomposition of the spinel-structured olivine [γ-(Mg,Fe)2SiO4] at 78 (3) GPa after laser heating at 2200 (100) K.