Ion-implanted graphite is studied by Raman scattering. Highly oriented pyrolytic graphite is implanted with ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$, and ${}_{}{}^{75}{}_{}{}^{}\mathrm{As}$ ions at 100 keV normally incident upon the $c$ face. Ion fluences in the range 1 × ${10}^{14}$ to 2.5 × ${10}^{16}$ ions/${\mathrm{cm}}^2$ are used. The lattice damage upon implantation is monitored by observation of the disorder-induced Raman line at ∼ 1355 ${\mathrm{cm}}^{-1\mathrm{}}$ in the first-order spectra and at ∼ 2970 ${\mathrm{cm}}^{-1\mathrm{}}$ in the second-order spectra. The Raman results indicate that an abrupt transformation to an amorphous surface layer occurs at a critical fluence which varies with the mass of the implanted ion. Results for first- and second-order Raman spectra are also presented for the same ion-implanted samples upon isochronal vacuum annealing at various annealing temperatures, showing a partial restoration of the graphite ordering. The second-order Raman spectra are even more sensitive than the first-order spectra to the creation of lattice damage by ion implantation and to the subsequent partial restoration of lattice order by annealing.

• Received 8 December 1980

DOI:https://doi.org/10.1103/PhysRevB.24.1027