TY - JOUR
T1 - Phase equilibria of Ll0-type order in Cu-Au-Pd and Cu-Au-Ni ternary systems
AU - Morimura, T.
AU - Matsumura, S.
AU - Hasaka, M.
AU - Tsukamoto, H.
N1 - Funding Information:
ACKNOWLEDGEMENTS The authors would like to express their gratitude to Professor Y. Tomokiyo and Messrs T. Manabe and E. Tanaka of the High-Voltage Electron Microscopy Laboratory, Kyushu University, for valuable suggestions and for assistance with the operation of the electron microscope. They are also grateful to Dr K. Udo of Nagasaki University for his fruitful suggestions and comments. This work was partly supported by the Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan.
PY - 1997/12
Y1 - 1997/12
N2 - The IKL-ALCHEMI (intersecting Kikuchi-line-atom-location by electron channeling-enhanced X-ray microanalysis) method of electron diffraction was employed to study the atomic configuration in Ll0-type ordered phases in Cu-Au-Pd and Cu-Au-Ni ternary alloys annealed at 573 K. In the Ll0 phase of Cu-Au-Pd, Au and Pd atoms tend to share the same sublattice, while Cu atoms prefer the other sublattice. If the sum of Au and Pd contents exceeds 50at.%, most Pd atoms still remain on the favourite sites, while excess Au atoms are driven to the opposite sublattice. In the ordered Cu-Au-Ni alloys. Ni atoms weakly prefer the Cu sublattice rather than the other for Au, but the distribution of Ni atoms depends on the alloy composition. Most Ni atoms reside on the Cu sublattice when the Au content is 50at.%. while about two thirds of Ni atoms are found on the Au sublattice in the alloy with 50at.% Cu. The cluster variation method (CVM) in the tetrahedral approximation explains well not only the experimental results of atomic configuration but also the equilibrium phase diagrams of both ternary systems. The appropriate values of parameters for pairwise interactions as well as four-body interactions of atoms have been determined in the framework of the CVM tetrahedral approximation.
AB - The IKL-ALCHEMI (intersecting Kikuchi-line-atom-location by electron channeling-enhanced X-ray microanalysis) method of electron diffraction was employed to study the atomic configuration in Ll0-type ordered phases in Cu-Au-Pd and Cu-Au-Ni ternary alloys annealed at 573 K. In the Ll0 phase of Cu-Au-Pd, Au and Pd atoms tend to share the same sublattice, while Cu atoms prefer the other sublattice. If the sum of Au and Pd contents exceeds 50at.%, most Pd atoms still remain on the favourite sites, while excess Au atoms are driven to the opposite sublattice. In the ordered Cu-Au-Ni alloys. Ni atoms weakly prefer the Cu sublattice rather than the other for Au, but the distribution of Ni atoms depends on the alloy composition. Most Ni atoms reside on the Cu sublattice when the Au content is 50at.%. while about two thirds of Ni atoms are found on the Au sublattice in the alloy with 50at.% Cu. The cluster variation method (CVM) in the tetrahedral approximation explains well not only the experimental results of atomic configuration but also the equilibrium phase diagrams of both ternary systems. The appropriate values of parameters for pairwise interactions as well as four-body interactions of atoms have been determined in the framework of the CVM tetrahedral approximation.
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U2 - 10.1080/01418619708214225
DO - 10.1080/01418619708214225
M3 - Article
AN - SCOPUS:0039562567
SN - 0141-8610
VL - 76
SP - 1235
EP - 1249
JO - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
JF - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
IS - 6
ER -