The regularities of high-fluence ion-induced graphitization of diamond

The Potential of High-Fluence Ion Irradiation for Processing and Recovery of Diamond Tools

“…The measurement of the electrical conductivity of irradiated CVD diamonds showed that the graphitization of the surface layer can also be obtained by irradiation with carbon ions. A decrease in conductivity at 400-600 • C is associated with the formation of nanocrystalline graphite, which has a lower conductivity [11,12]. It can be seen from the figure that a graphite-like layer can also be obtained by irradiating diamond with carbon ions at a temperature corresponding to the maximum conductivity of the modified layer.…”

“…A sharp increase in conductivity begins at a T of about 150 • C; then, after passing the maximum of about 300 • C, a decrease in the conductivity is observed, which is small for irradiation with argon and significant for irradiation with carbon ions. A decrease in conductivity at 400-600 °C is associated with the formation of nanocrystalline graphite, which has a lower conductivity [11,12]. It can be seen from the figure that a graphite-like layer can also be obtained by irradiating diamond with carbon ions at a temperature corresponding to the maximum conductivity of the modified layer.…”

“…At not-too-high fluences ν(x) ≈ Φ• (x)/n 0 , where the fluence Φ = ϕ•τ is equal to the product of the ion beam flux ϕ and irradiation time τ, n 0 is the atomic target concentration [19]. At high fluences, dynamic equilibrium conditions are established, in which the profiles of the concentration of implanted particles and radiation damage become stationary [11]. The stationary damage depth profile ν st (x) is calculated as follows:…”

“…It should be noted that at T a ≥ 1300 • C, the transformation of diamond into graphite begins. More efficient graphitization occurs with "hot" irradiation (Figure 5) (see [11]). A sharp increase in conductivity begins at a T of about 150 • C; then, after passing the maximum of about 300 • C, a decrease in the conductivity is observed, which is small for irradiation with argon and significant for irradiation with carbon ions.…”

“…The influence of high-fluence ion irradiation by 10-30 keV Ar + , Ne + , N + , N 2 + and C + ions at temperatures from 30 to 720 • C on the conductivity and microstructure of a polycrystalline diamond surface layer was experimentally studied in [11,12]. The increase in diamond temperature during irradiation leads to ion-induced graphitization at T ir > T gr ≈ 200 • C. The Raman spectra indicate that irradiation with neon and argon ions at temperatures of the diamond more than T ir > 500 • C leads to the formation of a nanocrystalline graphite layer that increases the resistivity of the irradiated layer.…”