Resolution with inelastic neutron

Tetramethylplumbane mixtures with tetramethylstannane were studied at 2 K by high resolution INS (inelastic neutron scattering), revealing rotational tunnelling transitions for the methyl groups146. 

As an example of the extreme energy resolution possible with inelastic neutron sattering, we include some recent experiments of Newbery et (17) on methane adsorbed on graphitized carbon blacks. Using a time-of-flight spectrometer and an incident... 

These are, with decreasing resolution on the time scale, the methods of infrared and Raman spectroscopy, dielectrical absorption and NMR spectroscopy, and inelastic neutron scattering. Thermodynamic properties depend on the long lifetime average structures, which are observed by X-ray and neutron scattering. For each of these methods, the descriptor structure has a different meaning. 

J.Z. Larese, D. Martin y Marero, D.S. Sivia C.J. Carlile (2001). Phys. Rev. Lett., 87, art. no. 206102. Tracking the evolution of interatomic potentials with high resolution inelastic neutron spectroscopy. 

Fig. 14. Inelastic neutron-scattering spectra of Ar/MgO(100) at 10 K. (a) Experimental spectra at incident energy of 7 meV for a 0.8 layer 2x3 structure note the difference between the experimental errors (vertical bars) in the gain and the loss energy ranges the triangle represents the experimental line shape reduced by a factor of 1/30. (b) Calculated spectrum for the 2x3 structure, in arbitrary units, after convoluting with the instrumental resolution of 0.3 meV at a neutron gain of 5 meV. (c) Calculated spectrum without broadening. The width of the peaks is due to the numerical step in the calculation of the dispersion branches. Baselines of curves (b) and (c) are shifted with respect to curve (a) (fi-om Ref 99).

Purely with optical means also the bandwidth of the quasiparticle bands could be determined and they range for the five investigated materials between 1 meV to 15 meV These bandwidths are in full agreement with calculated bandwidths from high-resolution photoemission at low temperatures (e.g., Patthey et al. 1990) or with the quasielastic line width of inelastic neutron scattering (e.g., Goldman et al, 1987) and they are also a measure of the Kondo temperature. 

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