First-principles simulations and Z-contrast imaging of impurities at <001> tilt grain boundaries in MgO

Technical Report · Sun Nov 30 23:00:00 EST 1997

DOI:https://doi.org/10.2172/564235· OSTI ID:564235

Yan, Y; Chisholm, M F; Pennycook, S J ^[1]; Duscher, G ^[1]; Maiti, A ^[2]; Pantelides, S T ^[1]

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1. Oak Ridge National Lab., TN (United States). Solid State Div.
2. Molecular Simulations Inc., Burlington, MA (United States)

First-principles density-functional calculations were used to study the effects of CA impurities on the {Sigma} = 5 (310) <001> tilt grain boundaries in MgO. An equilibrium structure and two metastable structures of the grain boundaries in pure MgO have been established. The calculations further demonstrated that Ca impurities segregate at particular sites in the metastable grain boundary and induce a structural transformation. This result is consistent with atomic resolution Z-contrast imaging. The calculations also found that the impurities at the grain boundaries do not induce states in the band gap. The mechanism of the transformation is also discussed.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 564235
• Report Number(s): ORNL/CP--95887; CONF-971201--; ON: DE98001845; BR: KC0202040
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM
CRYSTAL-PHASE TRANSFORMATIONS
GRAIN BOUNDARIES
IMPURITIES
MAGNESIUM OXIDES
SEGREGATION
THEORETICAL DATA