title: Localized defects in radiation-damaged zircon
abstract: The crystal structure of a radiation-damaged natural zircon, ZrSiO(4) (alpha-decay radiation dose is ca 1.8 x 10(18) alpha-decay events g(-1)), has been determined. The anisotropic unit-cell swelling observed in the early stages of the amorphization process (0.17% along the a axis and 0.62% along the c axis compared with the undamaged material) is a consequence of the anisotropy of the expansion of ZrO(8) polyhedra. Larger anisotropic displacement parameters were found for Zr and O atoms, indicating that the distortion produced by alpha particle-induced localized defects mainly affects the ZrO(8) unit. The overall shape of SiO(4) tetrahedra remains essentially undistorted, while Si-O bonds are found to lengthen by 0.43%.
authors: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, England. rios@esc.cam.ac.uk.
authors: S
authors: Rios
authors: T
authors: Malcherek
authors: EK
authors: Salje
authors: C
authors: Domeneghetti