The technique of producing binary alloy films containing composition modulations with wavelengths between 0.8 and 8.0 nm is discussed. A new method of measuring interatomic potentials up to the sixth neighbor is developed by utilizing modulated films of  and  textures. The theoretical treatment, which is based on the microscopic theory of diffusion, allows for the estimation of the interatomic potentials from the wavelength dependence of the effective diffusion coefficients D̃B on the two crystallographic orientations. The D̃B values are measured from the decay rate of the X-ray diffraction satellite intensities produced by the modulation. Results for D̃B are presented for a number of systems, such as CuNi, CuPd, AuNi, AgPd and AgAu. The stability of concentration waves at various temperatures is also discussed and an example of the determination of the spinodal temperature for the CuNi modulated films is given. The effect of loss of coherency on the long-wavelength modulations and the appearance of screening singularities in the D̃B values are also considered.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry