research papers
Within the scope of the self-consistent-field (SCF) and mean-SCF approximations, the Matsubara–Kanzaki–Krivoglaz lattice-statics method as well as the Krivoglaz–Clapp–Moss approach, the kinematic diffuse scattering intensities near the Bragg reflection caused by the atomic short-range order (taking into account the long-range magnetic order) in a (para)magnetic bulk face-centred cubic Ni–Fe alloy are investigated in detail. The reciprocal-space symmetry analysis of both the `direct' `electrochemical' and short-range `exchange' interactions as well as the long-range `indirect' `strain-induced' contribution to the Fourier components of interatomic `mixing' energies and the diffuse scattering intensity contributions near the `fundamental' Γ(000)-point is carried out. In the Γ-point vicinity, the rigorous symmetry regularities for all the energy and diffuse scattering intensity contributions are formulated. As revealed, the short-range order (SRO) diffuse scattering intensity behaves conditionally as for from all the reciprocal-space directions, which is in contrast to the conventional Huang diffuse scattering intensity conditionally definable as for . Special attention is paid to the analytic (i.e. azimuthal) and nonanalytic (i.e. first-kind-jump-discontinuous `radial') behaviours of the Fourier components of interatomic `mixing' energies or the SRO intensities near and at the Γ(000)-point.
Keywords: interatomic interactions; magnetic impurity interactions; short-range order; diffuse scattering; statistical thermodynamics.
Supporting information
Portable Document Format (PDF) file https://doi.org/10.1107/S0108767313018138/ib5019sup1.pdf |