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Title: Fast crystallization of amorphous Gd{sub 2}Zr{sub 2}O{sub 7} induced by thermally activated electron-beam irradiation

We investigate the ionization and displacement effects of an electron-beam (e-beam) on amorphous Gd{sub 2}Zr{sub 2}O{sub 7} synthesized by the co-precipitation and calcination methods. The as-received amorphous specimens were irradiated under electron beams at different energies (80 keV, 120 keV, and 2 MeV) and then characterized by X-ray diffraction and transmission electron microscopy. A metastable fluorite phase was observed in nanocrystalline Gd{sub 2}Zr{sub 2}O{sub 7} and is proposed to arise from the relatively lower surface and interface energy compared with the pyrochlore phase. Fast crystallization could be induced by 120 keV e-beam irradiation (beam current = 0.47 mA/cm{sup 2}). The crystallization occurred on the nanoscale upon ionization irradiation at 400 °C after a dose of less than 10{sup 17} electrons/cm{sup 2}. Under e-beam irradiation, the activation energy for the grain growth process was approximately 10 kJ/mol, but the activation energy was 135 kJ/mol by calcination in a furnace. The thermally activated ionization process was considered the fast crystallization mechanism.
Authors:
; ; ; ;  [1] ;  [2] ;  [3] ; ;  [1] ;  [2] ;  [1] ;  [2] ;  [1] ;  [2] ;  [2]
  1. College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)
  2. (China)
  3. College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China)
Publication Date:
OSTI Identifier:
22493002
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ACTIVATION ENERGY; BEAM CURRENTS; CALCINATION; COPRECIPITATION; CRYSTALLIZATION; DOSES; ELECTRON BEAMS; FLUORITE; GADOLINIUM COMPOUNDS; GRAIN GROWTH; IONIZATION; IRRADIATION; KEV RANGE; MEV RANGE; NANOSTRUCTURES; PYROCHLORE; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; ZIRCONATES