Evaluation of diffusion broadened Mössbauer spectra in single crystals of FCC metals

Emission Mössbauer spectroscopy in the Co–O system under high oxygen pressure

“…A frequency u satisfies the following relationship uZ ðDGqÞ=hgi; where the symbol DG stands for the excess source linewidth due to the diffusional motions, and q denotes the wave number of the emitted 14.41-keV Mössbauer radiation (7.31 Å K1 ) to a very good approximation. A geometrical factor hgi for the random sample approximation and for the uncorrelated jumps to the nearest neighbor positions in the FCC lattice satisfies the following relationship [10][11][12]:…”

“…Diffusional broadening of the Mössbauer resonance line [9] can be used to determine the temperature dependence of the diffusion coefficient D [10][11][12]. In order to calculate D vs. temperature, one needs to make some assumptions about the microscopic mechanism of diffusion.…”

“…Additionally, the following approximations have been made: the source is resonantly thin having the intrinsic line shape described by the Lorentzian profile. A broadening is small enough to neglect non-Lorentzian contribution to the emission profile [10]. Moreover, the Mössbauer atom jumps to the nearest neighbor sites in the FCC lattice and the uncorrelated nearest neighbor jumps are considered as the uncorrelated events leading to the diffusion [10].…”

“…Moreover, the Mössbauer atom jumps to the nearest neighbor sites in the FCC lattice and the uncorrelated nearest neighbor jumps are considered as the uncorrelated events leading to the diffusion [10]. Under such circumstances, a diffusion coefficient of the iron impurity can be expressed as follows [10]:…”

7-W single-mode thulium-doped fibre laser pumped at 1230 nm

“…Mössbauer spectroscopy in the energy domain [1] is a very useful tool to look upon microscopic mechanisms of diffusion [2][3][4]. In order to study the behaviour of extremely diluted impurities one has to resort to emission Mössbauer spectroscopy [5][6][7].…”