Epitaxial recrystallization of Rb-irradiated α-quartz during thermal annealing in air

Solid phase epitaxial regrowth of the amorphized layer in α-quartz induced by Rb ion implantations has been studied by thermal annealing in air at 800-1200 K. The Rb+ ions were implanted at 175 keV to fluences of 1.0x1016-3.4x1016 ions/cm2. The damage profiles and Rb depth distributions were measured by Rutherford backscattering and channeling spectroscopy. Complete epitaxial recrystallization was achieved for the samples implanted with 2.5x1016 Rb/cm2 after a 1 h annealing in air at 1173 K. The regrowth process occurs in two steps and has activation energies of EaL=0.6±0.1 and EaH=3.6±0.4 eV. The recrystallization rate was found to increase for increasing implanted Rb fluence. The results are discussed by considering the topological structures and network connectivity of SiO2