Solid phase epitaxial regrowth of α-quartz amorphized by ion implantation of dopants appears to be an attractive method for processing this optoelectronically important material. In an attempt to optimize solid phase epitaxy of α-quartz, we have studied the case of 50 keV 23Na ion implantation and annealing in an 18O atmosphere at 500-850 °C. The damage profiles were monitored by means of Rutherford backscattering-channeling, while the out-diffusion of the implanted 23Na and the 16O ⇔ 18O exchange in the near-surface layers were investigated using the time-of-flight Elastic Recoil Detection analysis technique. As in the case of Cs-irradiated quartz, full epitaxial recrystallization was observed to occur for Na-irradiated quartz, however, at the lower temperature of approximately 650 °C (vs. 875 °C for Cs). Based on these observations, Na appears to offer a good compromise between a low recrystallization temperature (required to avoid oxidation of the dopants) and full recrystallization of the matrix. © 2002 Elsevier Science B.V. All rights reserved.