Ternary atom site location in L1 sub 2 -structured intermetallic compounds
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (US)
Ternary sublattice site occupancy in two L1{sub 2}-structured intermetallic compounds were evaluated by a transmission electron microscope technique called ALCHEMI, or atom site location by channeling enhanced microanalysis, and by x-ray diffractometry, through measuring the relative integrated intensity of fundamental and superlattice x-ray diffraction peaks. The x-ray diffractometry showed that in nickel-rich Ni{sub 3}Al+Hf hafnium was found to occupy preferentially the aluminum sublattice, and in a multiphase alloy an L1{sub 2}-structured phase with the composition Al{sub 74.2}Ti{sub 19}Ni{sub 6.8} nickel atoms showed a strong preference for the titanium sublattice. The ALCHEMI data broadly agreed with the x-ray results for Ni{sub 3}Al but gave completely the opposite result, i.e., a preference of nickel for the titanium sublattice, for Al{sub 3}Ti. The methods of ALCHEMI and x-ray diffractometry are compared, and it is concluded that ALCHEMI data may be easily convoluted by peak overlap and delocalization effects.
- DOE Contract Number:
- FG02-87ER45311
- OSTI ID:
- 5695589
- Journal Information:
- Journal of Materials Research; (USA), Journal Name: Journal of Materials Research; (USA) Vol. 6:5; ISSN JMREE; ISSN 0884-2914
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
HAFNIUM ALLOYS
INTERMETALLIC COMPOUNDS
MICROSCOPY
NICKEL ALLOYS
SCATTERING
TERNARY ALLOY SYSTEMS
TITANIUM ALLOYS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION