Point defect study of CuTi and CuTi sub 2

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1991.0473· OSTI ID:5622766

Shoemaker, J R; Lutton, R T; Wesley, D; Wharton, W R; Oehrli, M L; Herte, M S; Sabochick, M J ^[1]; Lam, N Q ^[2]

---

1. Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson AFB, Ohio 45433-6583 (US)
2. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (US)

The energies and configurations of interstitials and vacancies in the ordered compounds CuTi and CuTi{sub 2} were determined using atomistic simulation with realistic embedded-atom potentials. The formation energy of an antisite pair was found to be 0.385 and 0.460 eV in CuTi and CuTi{sub 2}, respectively. In both compounds, the creation of a vacancy by the removal of either a Cu or Ti atom resulted in a vacant Cu site, with an adjacent antisite defect in the case of the Ti vacancy. The vacant Cu site in CuTi was found to be very mobile within two adjacent (001) Cu planes, with a migration energy of 0.19 eV, giving rise to two-dimensional migration. The vacancy migration energy across (001) Ti planes, however, was 1.32 eV, which could be lowered to 0.75 or 0.60 eV if one or two Cu antisite defects were initially present in these planes. In CuTi{sub 2}, the vacancy migration energy of 0.92 eV along the (001) Cu plane was significantly higher than in CuTi. The effective vacancy formation energies were calculated to be 1.09 eV and 0.90 eV in CuTi and CuTi{sub 2}, respectively. Interstitials created by inserting either a Cu or Ti atom had complicated configurations in which a Cu {l angle}111{r angle} split interstitial was surrounded by two or three Ti antisite defects. The interstitial formation energy was estimated to be 1.7 eV in CuTi and 1.9 eV in CuTi{sub 2}.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5622766
• Journal Information: Journal of Materials Research; (USA), Journal Name: Journal of Materials Research; (USA) Vol. 6:3; ISSN JMREE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
COMPLEXES
COPPER ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ENERGY
FORMATION FREE ENERGY
FREE ENERGY
INTERSTITIALS
PHYSICAL PROPERTIES
POINT DEFECTS
SIMULATION
THERMODYNAMIC PROPERTIES
TITANIUM ALLOYS
VACANCIES