Formation of surface diamond-like nanostructures on graphite induced by highly charged ion irradiation
Date
2011-03-28
Authors
Makgato, Thuto Nelson
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Abstract
The interaction of Antimony Slow Highly Charged Ions (SHCIs) of different charge states with Highly Oriented Pyrolitic Graphite (HOPG) is studied in terms of morphology and electronic modification of single-ion impact induced nanodefects. Results are presented in terms of non-contact Atomic Force Microscopy (NC-AFM) analysis, Raman spectroscopy, Photoluminescence and Scanning and Tunneling Spectroscopy (STS). A charge state dependence of radiation damage and nanodefect dimensions is observed using Raman spectroscopy and NC-AFM analysis respectively. Surface treatment of the nanodefects by annealing in a hydrogen atmosphere, induce modification of nanodefect dimensions and the corresponding electronic states as observed from NC-AFM analysis and STS. STS conducted on the treated nanodefects shows significant modification of the electronic energy band gap in Sb18+ and Sb22+ impact regions. The materials produced in this work by SHCI impact and surface treatment are believed to be diamond-like carbon (DLC) with electronic energy band gaps of approximately 2.05 eV and 2.33 eV corresponding to Sb18+ and Sb22+ impact regions respectively. DLC nanostructures observed in the present study could provide a host matrix for N-V luminant centers which can be used as single photon sources to fabricate patterned qubits using the Electron Beam Ion Trap (EBIT) for purposes of demonstrating scalable room temperature quantum information devices.