Abstract
The optical properties of damaged periodic and aperiodic domains created by Pb+ 280 keV and Au4+
10 MeV implantation of zircon were studied using micro-infrared IR and micro-Raman spectroscopy. The
Pb+ and Au4+ irradiations caused a dramatic decrease in the IR reflectivity similar to that observed for
metamict natural zircon. The irradiation with 10 MeV Au4+ ions to fluences of 11015 Au4+ ions/cm2 also
results in the formation of an amorphized phase similar to that observed in metamict zircon. These results show
that high-energy, heavy-ion irradiations provide a good simulation of the ballistic effects of the recoil nucleus
of an alpha-decay event and, in both cases, the result is the creation of aperiodic domains. Additional IR and
Raman features were recorded in samples irradiated with 280 keV Pb+ ions to fluences of 11014 and 1
1015 Pb+ ions/cm2, indicating the formation of an irradiation-induced additional phases. The frequencies
of the features are consistent with lead silicates, ZrO2, and SiO2. The results show that spectral features of the
Au4+- and Pb+-irradiated zircon are different from those of quenched ZrSiO4 melts, and the finding further
confirms that the amorphous state produced by high-energy ion irradiations is structurally different from the
glassy state that results from quenching a high temperature melt. In contrast to significant changes in the
frequency and width of the Raman 3 band observed in metamict zircon, the Pb+ and Au4+ irradiations do not
cause similar variations, indicating that the remaining zircon crystalline domains in irradiated samples have a crystalline structure with fewer defects than those of metamict zircon.