Thumbnail
Access Restriction
Open

Author Huang, Zhangyi ♦ Qi, Jianqi ♦ Zhou, Li ♦ Feng, Zhao ♦ Yu, Xiaohe ♦ Gong, Yichao ♦ Yang, Mao ♦ Wei, Nian ♦ Shi, Qiwu ♦ Lu, Tiecheng
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword 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
Abstract 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.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-12-07
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 118
Issue Number 21


Open content in new tab

   Open content in new tab