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Title: Reduced grain boundary energies in rare-earth doped MgAl 2O 4 spinel and consequent grain growth inhibition

In this paper, grain growth inhibition in MgAl 2O 4 spinel nanostructure was achieved by grain boundary (GB) segregation of rare-earth dopants. Microcalorimetric measurements showed that dense spinel compacts doped with 3 mol% of R 2O 3 (R = Y, Gd, and La) had decreased GB energies as compared to the undoped spinel, representing reduction in the driving force for grain growth. Segregation energies of the three dopants to the Σ3 (111) GB were calculated by atomistic simulation. The dopants with higher ionic radius tend to segregate more strongly to GBs. The GB energies were calculated from atomistic simulation and, consistent with experiments, a systematic reduction in GB energy with dopant ionic size was found. Finally, high temperature grain growth experiments revealed a significant reduction of grain growth in the doped nanostructures as compared to the undoped one, which was attributed to increased metastability or possibly also a GB dragging originated from the dopant segregation.
 [1] ;  [2] ;  [1] ;  [2] ;  [1]
  1. Univ. of California, Davis, CA (United States). Dept. of Materials Science and Engineering. NEAT ORU
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0955-2219
Grant/Contract Number:
AC52-06NA25396; DMR-1609781
Accepted Manuscript
Journal Name:
Journal of the European Ceramic Society
Additional Journal Information:
Journal Volume: 37; Journal Issue: 13; Journal ID: ISSN 0955-2219
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF)
Country of Publication:
United States
36 MATERIALS SCIENCE; Nanocrystals; Thermodynamics; Grain boundary energy; Oxide
OSTI Identifier: