Inelastic excitations

Inelastic scattering processes are not used for structural studies in TEM and STEM. Instead, the signal from inelastic scattering is used to probe the electron-chemical environment by interpreting the specific excitation of core electrons or valence electrons. Therefore, inelastic excitation spectra are exploited for analytical EM. 

Fig. 9.34 Monitoring of inelastic excitations by nuclear resonant scattering. The sidebands of the excitation probability densities for phonon creation, S(E), and for annihilation, S —E), are related by the Boltzmann factor, i.e., S(—E) = S E) tTvp —Elk T). This imbalance, known as detailed balance, is an intrinsic feature of each NIS spectrum and allows the determination of the temperature T at which the spectrum was recorded...

In summary, the movement of a high-energy electron in a solid may be described by a set of three Equations (1), (4) and (6). From these equations we may conclude that for high-energy electron diffraction the problem of multiple elastic and inelastic scattering by a solid is entirely determined by two functions, i.e. (1) the Coulomb interaction potential averaged over the motion of the crystal particles (V(r)> and (2) the mixed dynamic form factor S(r, r, E) of inelastic excitations of the solid. 

First, we will discuss concentration dependences and the scaling behaviour of these properties with Z. Later, we will discuss temperature dependencies taking into account effects due to the inelastic excitation of phonon-rotons. 

Fourier times accessible to spin-echo spectroscopy range from 1 ps-100 ns. i.e., the energy resolution is better by two orders of magnitude than with the backscattermg technique. The scientific fields under interest are polymer dynamics, glass transitions, dynamics of magnetic disordered compounds, colloids, microemulsions, or inelastic excitations (rotons in He). 

The elastic scattering of protons by is reported to show anomalies between 1.07 and 1.78 MeV [32], and phase shift analyses have been made. With higher proton energies, attention has concentrated on the inelastic excitation of the... 

Inelastic excitation via a-particles (i.e., a,a ) has provided the bulk of the data on the highly collective giant monopole resonance, often called the breathing mode. Data of this type (O Fig. 3.30) have been used to extract the nuclear incompressibility of finite nuclei, and with the aid of models, the incompressibility of symmetric matter (see Sect. 3.7). 

It seems then that the LLT in liquid Cs affects the microscopic dynamics very litde, at least as far as the high-frequency speed of sound is concerned. However, another picture appears if we look at the relaxational dynamics, that is, the relaxation time Tq, and the microscopic relaxation parameter F, as shown in Fig. 5 r describes the contribution to the broadening of the inelastic excitations coming from the microscopic relaxation. Inspecting Fig. 5b, we see that the a-relaxation time decreases on increasing pressure in the first pseudo-Brillouin zone, that is, up to q/qo = 0-5. The decrease is gradual and it is actually more important between 1 and 3.5 GPa than at higher pressures. This thus seems to be a density-dependent... 

Fig. 47. QE linewidth (solid circles) and inelastic excitation energy (solid squares) observed in TmSe as function of temperature. (Adapted from Holland-Moritz 1983.)...

Tm systems they depend monotonously on the lattice parameter, i.e., with increasing volume available for the valence-fluctuating Tm ion both the quasielastic width and the inelastic excitation energy decrease (Holland-Moritz 1983). 

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