Dynamics of electron density in a medium revealed by Mossbauer time-domaininterferometry - art. no. 144303

Nuclear resonant scattering of synchrotron radiation allows the detection o f energy transfers in the sample in the order of DeltaE/E approximate to 10 (-13). This extreme energy resolution is used in Mossbauer time domain inte rferometry to provide an inelastic scattering method similar or even superi or to high resolution inelastic neutron scattering. The interferometer cons ists of two nuclear targets as interferometer arms, and a nonresonant sampl e placed in between, and detects slow dynamics of the electron density in a time range of nuclear response, typically from 10 ns to 200-500 ns. It has access to scattering vectors from 0.1 Angstrom to beyond 10 Angstrom. The general theory of the interferometer is provided and it is evaluated how th e Van Hove correlation function presenting the electron density fluctuation s of the sample in space and time can be measured. Exemplarily, it is shown how the temporal behavior of diffusion can be studied with diffusivities i n the range from 10(-16) to 10(-13) m(2)/s.