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Theoretical Study Of The Environmental Effects On The Hyperfine Fields Of Ni And Fe In Ni0.75fe0.25, H. Ebert, H. Winter, B. Gyorffy, Duane D. Johnson, F. J. Pinski
Theoretical Study Of The Environmental Effects On The Hyperfine Fields Of Ni And Fe In Ni0.75fe0.25, H. Ebert, H. Winter, B. Gyorffy, Duane D. Johnson, F. J. Pinski
Duane D. Johnson
The dependence of the hyperfine fields Bhf of Ni and Fe in Ni0.75Fe0.25 on the surrounding atomic configuration has been studied by performing charge selfconsistent 6 shell-cluster Korringa-Kohn-Rostoker Coherent Potential Approximation (KKR-CPA) bandstructure calculations. By replacing the CPA- scatterers in the various shells around the central atom by Ni - or Fe-atoms, respectively, it could be shown that the hyperfine fields vary linearly with the number of Fe-atoms within a given shell and that the changes of Bhf due to simultaneous changes of the atomic configurations of different shells are additive. The changes of the hyperfine fields upon ordering of …
The Further Geometry Of Grain Boundaries In Hexagonal Close-Packed Metals, Fu-Rong Chen, Alexander H. King
The Further Geometry Of Grain Boundaries In Hexagonal Close-Packed Metals, Fu-Rong Chen, Alexander H. King
Alexander H. King
A technique is given for finding partial DSC vectors appropriate to crystals with more than one atom per lattice site. The DSC lattice is made up of vectors that represent displacements of one crystal with respect to the other that leave the boundary structure shifted, but not complete. A new, rapid method for finding the step vectors associated with perfect DSC dislocations is described. Partial DSC vectors and step vectors for perfect DSC dislocations in hexagonal close-packed crystals are determined. The availability of reactions between lattice partial dislocations and grain boundaries in hexagonal close-packed crystals is also assessed.
Interaction Between Magnetic And Compositional Order In Ni‐Rich Ni C Fe1−C Alloys (Invited), J. B. Staunton, Duane D. Johnson, B. L. Gyorffy
Interaction Between Magnetic And Compositional Order In Ni‐Rich Ni C Fe1−C Alloys (Invited), J. B. Staunton, Duane D. Johnson, B. L. Gyorffy
Duane D. Johnson
We have developed a first‐principles electronic theory of concentration fluctuations in spin polarized binary alloys. It is a mean field theory of the state of compositional order and it is based on the local spin density (LSD) approximation for describing the electrons. The usual averages over the statistical mechanical ensemble are carried out with the aid of the self‐consistent Korringe–Kohn–Rostoker coherent‐potential approximation (SCF‐KKR‐CPA). To illustrate the main consequences of the theory we study the compositional short‐range order in the Ni c Fe1−c alloy system. We find that the ordering energy is almost entirely of magnetic origin.