In-situ TEM studies of the radiation tolerance of ceramics
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Date
2016-02-04
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Publisher
Australian Microscopy and Microanalysis Society
Abstract
For the nuclear industry ion-irradiation has been used to simulate recoil damage from alpha decay, and exposure to neutrons in fission and fusion reactors [1]. The particular focus of this research is on the crystalline to amorphous transition facilitated by exposure to accelerated ions. The complex ceramic oxides chosen for this study, Ln2TiO5 (Ln = lanthanides and yttrium), have several uses within the nuclear industry. The compound Dy2TiO5 has been used within WWER type reactors due to its good resistance to irradiation induced swelling and structural failure [2]. Of particular interest are the cubic symmetry compounds with defect fluorite structure, which gives good radiation response. Previous studies show the series of Ln2TiO5 compounds may take on a variety of crystal symmetries depending on the lanthanide size and fabrication conditions used [3, 4]. The study of ion-irradiation response was carried out using the in-situ approach where the test materials were exposed to 1 MeV Kr2+ ions and monitored for their transition from crystalline to amorphous state. This was carried out using the intermediate voltage electron microscope (IVEM)-Tandem facility at Argonne National Laboratory. The critical dose of irradiating ions, Dc, required to render the Ln2TiO5 completely amorphous was determined by monitoring selected area electron diffraction patterns for loss of diffraction spots (Bragg maxima) and replacement with diffuse rings. Within the Ln2TiO5 series of compounds studied a linear relationship appears between the radii of the lanthanide and the radiation response. This follows a similar trend found in related pyrochlore compounds. Possible explanations for this trend are investigated. For the nuclear industry ion-irradiation has been used to simulate recoil damage from alpha decay, and exposure to neutrons in fission and fusion reactors [1]. The particular focus of this research is on the crystalline to amorphous transition facilitated by exposure to accelerated ions. The complex ceramic oxides chosen for this study, Ln2TiO5 (Ln = lanthanides and yttrium), have several uses within the nuclear industry. The compound Dy2TiO5 has been used within WWER type reactors due to its good resistance to irradiation induced swelling and structural failure [2]. Of particular interest are the cubic symmetry compounds with defect fluorite structure, which gives good radiation response. Previous studies show the series of Ln2TiO5 compounds may take on a variety of crystal symmetries depending on the lanthanide size and fabrication conditions used [3, 4]. The study of ion-irradiation response was carried out using the in-situ approach where the test materials were exposed to 1 MeV Kr2+ ions and monitored for their transition from crystalline to amorphous state. This was carried out using the intermediate voltage electron microscope (IVEM)-Tandem facility at Argonne National Laboratory. The critical dose of irradiating ions, Dc, required to render the Ln2TiO5 completely amorphous was determined by monitoring selected area electron diffraction patterns for loss of diffraction spots (Bragg maxima) and replacement with diffuse rings. Within the Ln2TiO5 series of compounds studied a linear relationship appears between the radii of the lanthanide and the radiation response. This follows a similar trend found in related pyrochlore compounds. Possible explanations for this trend are investigated.
Description
Keywords
Transmission electron microscopy, Ceramics, Irradiation, Ions, Rare earths, Fluorite, Pyrochlore
Citation
Aughterson, R. D., Cairney, J., Zaluzec, N. J. & Lumpkin, G. R. (2016). In-situ TEM studies of the radiation tolerance of ceramics. Paper presented to ACMM24 : Australian Conference on Microscopy and Analysis : Melbourne Convention and Exhibition Centre, 31 Jan-4 Feb 2016, (pp. 66).