A study of the natural ?-recoil damage in zircon by infrared spectra

Abstract

Natural α-recoil damage of 30 natural zircon specimens from Ceylon have been examined by studying the infrared absorption spectra from 1 to 15 μm. Two synthetic zircon specimens were also studied as undamaged reference specimens. The ir absorption coefficient at 6 μm (1666 cm⁻¹) was found to be a function of radiation damage. The ir data can be explained by a dual damage mechanism. The initial damage process produces degradation of the v ₃ vibrational mode in the ir spectra which can be explained by deformation of SiO₄ tetrahedra, whereas the predominant effect of the advanced stage of radiation damage is the breakdown of the zircon lattice into SiO₂ and ZrO₂ which causes a skewing of the v ₃ absorption band. These data substantiate the model of Pellas and clarify the dualistic nature of the radiation damage mechanism.