Cooperative structural effects in relaxing Pd-Er-H and Fe-C systems

Abstract

The dynamics of oscillating structural changes in nonequilibrium Fe-C and Pd-Er-H systems is studied. For Fe-C it is established that the Fourier spectrum of the time dependence of its Mossbauer spectra is similar to the Fourier transform of systems in a state of dynamic chaos on which several long-wavelength modes are superposed. The structural-oscillatory effects for Pd-Er-H consist of a combination of oscillatory processes, corresponding to the appearance and partial dissipation of H-D-M complexes, vibrational changes in the ratio of the fractions of the erbium-rich and-poor phases, and the difference of the compositions of these phases. The oscillations have a multimode character with periods increasing with time. Thus, cooperative effects associated with collective interactions of the matrix atoms, defects, and “perturbing” impurities such as hydrogen and oxygen atoms are clearly seen in the processes studied. It is shown that the synergetic concept in the spirit of the system of nonlinear Lorentz equations is useful for giving a macroscopic description of the observed defects.