Within the framework of the lattice-statics and static fluctuation-waves' methods, the available energies of strain-induced interaction of interstitial-interstitial, interstitial-substitutional and substitutional-substitutional impurity atomic pairs are collected and analysed for f.c.c.-(Ni,Fe)-C solutions allowing for discrete atomic structure of the host-crystal lattice. The lattice spacings, elasticity moduli and/or quasi-elastic force parameters of the host-crystal lattice, and concentration coefficients of the dilatation of solid-solution lattice due to the respective solutes are selected as the input numerical experimental data used. The above-mentioned interaction energies prove to have non-monotonically decreasing ('quasi-oscillating') and anisotropic dependences on discrete interatomic radius-vector, and themselves are strong and long-range. In all f.c.c.-(Ni,Fe)-base solutions, there is strain-induced attraction in many co-ordination shells. In general, the strain-induced interaction between impurity atoms in γ-Fe is weaker than in α-Ni (but in some solid solutions, it may prove to be of the same order). The verification of applicability of the approximation of strain-induced interaction of impurities for f.c.c.-(Ni,Fe)-C alloys (by means of analysis of thermodynamic C activity and 'short-range order' parameters of C-atoms' distribution revealed by Mössbauer spectroscopy) showed that it must be supplemented with additional short-range ('electrochemical') repulsion in the first co-ordination shell. Nevertheless, in any case, the strain-induced interaction of impurity atoms must be taken into account for analysis of structure and properties of f.c.c.-(Ni,Fe)-base solutions. The Monte Carlo simulation procedures applied for constitution of a nanoscale Fe-C-austenite crystallite and based on analysis of the dependences of numbers of the different atomic configurations on C-C interatomic-interaction en- Defect and Diffusion Forum Vols. 280-281 (2008) pp 29-78 online at http://www.scientific.net librium intensity values, the magnetic contribution to the 'mixing' energy of atoms (in low-spin states) of this alloy facilitates its atomic ordering, and the presence of atoms with essentially different spins may cause the virtually abrupt phase transition from paramagnetic state into magnetic one. The optimal sets of exchange-interaction energy parameters for f.c.c. Ni-Fe alloy are selected. As shown, the doping with small amounts of interstitial C impurities most likely increases ferromagnetic component of bond of Ni spins with Fe spins, reduces ferromagnetic component of bond of Ni spins with Ni spins, and increases antiferromagnetic component of bond of Fe spins with Fe spins in an f.c.c.-Ni-Fe alloy.
30Defects and Diffusion in Ceramics X article, for the first time in the state-of-the-art review literature. Actually, it is one of the main means of achievement of the goal, for the sake of which a given article was written, viz. the presented results of reasonable comparison and analysis of own original knowledg...