In situ TEM observation of alpha-particle induced annealing of radiation damage in Durango apatite. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Li, Weixing; Shen, Yahui; Zhou, Yueqing; Nan, Shuai; Chen, Chien-Hung; Ewing, Rodney
• Is Part Of: Scientific reports. Volume 7:Issue 1(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-12
• Subjects: Natural history -- Research -- Periodicals; Biology -- Research -- Periodicals; Physical sciences -- Research -- Periodicals; Earth sciences -- Research -- Periodicals; Environmental sciences -- Research -- Periodicals; 502.85
• DOI: 10.1038/s41598-017-14379-9
• Languages: English
• ISSNs: 2045-2322

Abstract

Abstract A major issue in thermochronology and U-Th-Pb dating is the effect of radiation damage, created byα -recoils fromα -decay events, on the diffusion of radiogenic elements (e.g ., He and Pb) in host mineral. Up until now, thermal events have been considered as the only source of energy for the recovery of radiation-damage. However, irradiation, such as from theα -particle of theα -decay event, can itself induce damage recovery. Quantification of radiation-induced recovery caused byα -particles duringα -decay events has not been possible, as the recovery process at the atomic-scale has been difficult to observe. Here we present details of the dynamics of the amorphous-to-crystalline transition process duringα -particle irradiations usingin situ transmission electron microscopy (TEM) and consecutive ion-irradiations: 1 MeV Kr2+ (simulatingα -recoil damage), followed by 400 keV He+ (simulatingα -particle annealing). Upon the He+ irradiation, partial recrystallization of the original, fully-amorphous Durango apatite was clearly evident and quantified based on the gradual appearance of new crystalline domains in TEM images and new diffraction maxima in selected area electron diffraction patterns. Thus, α -particle induced annealing occurs and must be considered in models ofα -decay event damage and its effect on the diffusion of radiogenic elements in geochronology and thermochronology.