ALCHEMI of L1{sub 2}-ordered Ni{sub 76}Al{sub 21}Hf{sub 3} and gamma prime particles

Conference · Mon Dec 30 23:00:00 EST 1996

OSTI ID:468868

Bentley, J; Anderson, I M ^[1]

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1. Oak Ridge National Lab., TN (United States)

Recent improvements to the atom location by channeling-enhanced microanalysis (ALCHEMI) technique now allow reliable measurements of site distributions in ordered alloys. Early zone-axis ALCHEMI of L1{sub 2}-ordered Ni{sub 3} Al-based alloys was plagued by ionization delocalization; for Ni{sub 76}Al{sub 21}Hf{sub 3} at <001> the fraction of Hf on the Al sublattice, pHf`Al` = 127%. Reanalysis by statistical ALCHEMI was no better, giving pHf`Al` = -220 {+-} 190%, contrary to the claims that delocalization effects should be minimized. The same data set analyzed with the reformulated ALCHEMI method yields PHf`Al` = 80 {+-}25%.

• DOE Contract Number: AC05-96OR22464
• OSTI ID: 468868
• Report Number(s): CONF-960877--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
HAFNIUM ALLOYS
MICROANALYSIS
NICKEL ALLOYS
SPATIAL RESOLUTION
SPECTRA
STATISTICS