Quantitative analysis of blistering upon annealing of hydrogen-ion-implanted diamond single crystals

Local blistering observed upon high-temperature annealing of natural diamond single crystals implanted by 350-keV hydrogen ions with a dose of 12 × 10¹⁶ cm^?2 is studied. Based on room-temperature measurements, Griffith cracking criterion, and gas law, model quantitative calculations of blister size (R _j = (0.361?5.568) × 10^?3 m, V _j = (307?9695) × 10^?18 m³) and the amount of molecules in a blister (n _j = (0.448?10.95) × 10¹³) are carried out for the first time. At room temperature, T ₁ = 293 K, the amount of local elastic stresses σ_ij in the upper layer of the diamond is counterbalanced by (inner) hydrogen pressure P _ij of the (σ _j1 = P _j1 = (2.968?6.439) × 10⁷ Pa). At annealing temperature T ₂ = 1693 K, the hydrogen pressure rises to P _j2 = (0.1717?0.8750) GPa. Under subsequent annealing at a still higher temperature, T ₃ = 1743 K, the pressure in the blisters might be expected to grow to P _j3 = (0.1747?0.9010) GPa; however, some of blisters collapse and thin diamond slices flake away.