skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Temperature effects on ion irradiation damage in MgAl{sub 2}O{sub 4} spinel single crystals

Abstract

The search for radiation resistant materials, particularly ceramics, for the applications in radiation environments has been an active area of research for the past few decades. Among the most well studied ceramics, stoichiometric magnesium aluminate spinel (MgAl{sub 2}O{sub 4}) has been found to be one of the most radiation resistant ceramics. Here, single crystalline samples of (MgAl{sub 2}O{sub 4}), <100> oriented, were irradiated at 100K and 670K with 370--400 keV Xe ions to doses of (1--2){times}10{sup 16} Xe/cm{sup 2}. The microstructures of irradiated samples were subsequently examined by cross-sectional transmission electron microscope. A uniform layer of amorphous phase was observed on the surface of spinel irradiated at 100K. At the end of the damage range underlying the amorphous layer, a disordered transition layer resided on the undamaged substrate. Both high resolution electron microscopy and microdiffraction revealed that the transition layer retained single crystallinity with epitaxial relationship to the underlying substrate. However, the intensity of <220> reflections in the transition layer was significantly weaker than that of the undamaged spinel. No evidence of amorphization was found in the spinel sample irradiated at 670K to a dose of 2{times}10{sup 16} Xe/cm{sup 2}. The <220> reflections exhibit only limited diminution in the heavilymore » damaged region. The observation of reduced intensity of <220> reflections or absent reflections suggests that spinel experiences a structural transition from its original cubic phase (a=0.808 nm) to a new cubic phase (a=0.404 nm). A transition sequence from the original phase to a metastable phase and then to an amorphous phase has been observed. The temperature dependence of metastable and amorphous phase formation has revealed that the accumulation efficiency of cation disorder decreases with increasing irradiation temperature due to the enhancement of interstitial-vacancy recombination.« less

Authors:
; ;  [1]
  1. Los Alamos National Lab., NM (United States). Materials Science and Technology Div.
Publication Date:
OSTI Identifier:
99459
Report Number(s):
CONF-941144-
ISBN 1-55899-275-8; TRN: 95:019118
Resource Type:
Book
Resource Relation:
Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 28 Nov - 9 Dec 1994; Other Information: PBD: 1995; Related Information: Is Part Of Microstructure of irradiated materials; Robertson, I.M. [ed.] [Univ. of Illinois, Urbana, IL (United States). Dept. of Materials Science and Engineering]; Rehn, L.E. [ed.] [Argonne National Lab., IL (United States). Materials Science Div.]; Zinkle, S.J. [ed.] [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.]; Phythian, W.J. [ed.] [AEA Technology-Harwell, Oxon (United Kingdom)]; PB: 588 p.; Materials Research Society symposium proceedings, Volume 373
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CERAMICS; PHYSICAL RADIATION EFFECTS; SPINELS; ALUMINIUM OXIDES; MAGNESIUM OXIDES; GRAIN ORIENTATION; TEMPERATURE DEPENDENCE; CRYSTAL-PHASE TRANSFORMATIONS; CRYSTAL DEFECTS; EXPERIMENTAL DATA; AMORPHOUS STATE

Citation Formats

Yu, N, Sickafus, K E, and Nastasi, M. Temperature effects on ion irradiation damage in MgAl{sub 2}O{sub 4} spinel single crystals. United States: N. p., 1995. Web.
Yu, N, Sickafus, K E, & Nastasi, M. Temperature effects on ion irradiation damage in MgAl{sub 2}O{sub 4} spinel single crystals. United States.
Yu, N, Sickafus, K E, and Nastasi, M. Fri . "Temperature effects on ion irradiation damage in MgAl{sub 2}O{sub 4} spinel single crystals". United States.
@article{osti_99459,
title = {Temperature effects on ion irradiation damage in MgAl{sub 2}O{sub 4} spinel single crystals},
author = {Yu, N and Sickafus, K E and Nastasi, M},
abstractNote = {The search for radiation resistant materials, particularly ceramics, for the applications in radiation environments has been an active area of research for the past few decades. Among the most well studied ceramics, stoichiometric magnesium aluminate spinel (MgAl{sub 2}O{sub 4}) has been found to be one of the most radiation resistant ceramics. Here, single crystalline samples of (MgAl{sub 2}O{sub 4}), <100> oriented, were irradiated at 100K and 670K with 370--400 keV Xe ions to doses of (1--2){times}10{sup 16} Xe/cm{sup 2}. The microstructures of irradiated samples were subsequently examined by cross-sectional transmission electron microscope. A uniform layer of amorphous phase was observed on the surface of spinel irradiated at 100K. At the end of the damage range underlying the amorphous layer, a disordered transition layer resided on the undamaged substrate. Both high resolution electron microscopy and microdiffraction revealed that the transition layer retained single crystallinity with epitaxial relationship to the underlying substrate. However, the intensity of <220> reflections in the transition layer was significantly weaker than that of the undamaged spinel. No evidence of amorphization was found in the spinel sample irradiated at 670K to a dose of 2{times}10{sup 16} Xe/cm{sup 2}. The <220> reflections exhibit only limited diminution in the heavily damaged region. The observation of reduced intensity of <220> reflections or absent reflections suggests that spinel experiences a structural transition from its original cubic phase (a=0.808 nm) to a new cubic phase (a=0.404 nm). A transition sequence from the original phase to a metastable phase and then to an amorphous phase has been observed. The temperature dependence of metastable and amorphous phase formation has revealed that the accumulation efficiency of cation disorder decreases with increasing irradiation temperature due to the enhancement of interstitial-vacancy recombination.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {9}
}

Book:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this book.

Save / Share: