Mdssbauer line shift

The temperature shift AV in the Mdssbauer lines is described by the equation... 

In an actual Mdssbauer transmission experiment, the radioactive source is periodically moved with controlled velocities, +u toward and —d away from the absorber (cf. Fig. 2.6). The motion modulates the energy of the y-photons arriving at the absorber because of the Doppler effect Ey = Eq + d/c). Alternatively, the sample may be moved with the source remaining fixed. The transmitted y-rays are detected with a y-counter and recorded as a function of the Doppler velocity, which yields the Mdssbauer spectrum, r(u). The amount of resonant nuclear y-absorption is determined by the overlap of the shifted emission line and the absorption line, such that greater overlap yields less transmission maximum resonance occurs at complete overlap of emission and absorption lines. 

In a Mdssbauer transmission experiment, the absorber containing the stable Mdssbauer isotope is placed between the source and the detector (cf. Fig. 2.6). For the absorber, we assume the same mean energy q between nuclear excited and ground states as for the source, but with an additional intrinsic shift A due to chemical influence. The absorption Une, or resonant absorption cross-section cr( ), has the same Lorentzian shape as the emission line and if we assume also the same half width , cr( ) can be expressed as ([1] in Chap. 1)... 

Table 7.12 Isomer shift 5 (with respect to the source of Au in Pt metal at 4.2 K), line width F, and percentage resonance effect / from Pt (99 keV) Mdssbauer measurements on platinum compounds at 4.2 K by Riiegg and coworkers [329, 332, 333]...

The Mdssbauer Eu spectrum of the composite powder at room temperature is shown in Fig. 3. It presents two lines characterizing by the isomeric shifts 8 = -12.6mm/c, width on half altitude 3.7 mm/c and 5 = +0.02 mm/c with the width on half altitude 4.1 mm/c, respectively. The first line is responsible for the paramagnetic ion Eu of the matrix, and the second line is responsible for the manifestation of Eu ". These isomeric shifts of Eu NGR spectrums in the composite correspond to the position of these ions in the lattice of EuO and EU2O3. 

Table 12. Mdssbauer spectra of polymeric iron phthalocyanine (6 experimental isomer shift, A quadrupole splittings, A relative areas of absorption lines, f line widths details s, 193)...

---