Reduced grain boundary energies in rare-earth doped MgAl2O4 spinel and consequent grain growth inhibition
- Univ. of California, Davis, CA (United States). Dept. of Materials Science and Engineering. NEAT ORU
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
In this paper, grain growth inhibition in MgAl2O4 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 R2O3 (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.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-06NA25396; DMR-1609781
- OSTI ID:
- 1369200
- Alternate ID(s):
- OSTI ID: 1706186
- Report Number(s):
- LA-UR-17-21471
- Journal Information:
- Journal of the European Ceramic Society, Vol. 37, Issue 13; ISSN 0955-2219
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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