Mossbauer absorption spectra

Fig. 7.25 Mossbauer absorption spectra of Zn metal obtained at 4.2 K and at two different pressures. The source is Ga/Cu (from [75])...

Fig. 7.27 Mossbauer absorption spectra of a polycrystalline Znp2 absorber recorded between 4.2 and 55.3 K. The source, Ga in a ZnO single crystal, was kept at 4.2 K (from [81])...

Mossbauer spectroscopy with started only in 1965, when Harris et al. [322] measured the Mossbauer absorption spectra of the 99 keV transition of Pt in platinum metal as a function of temperature (between 20 and 100 K) and of absorber thickness and derived the temperature dependence of the Debye-Waller factor. 

Fig. 8.21 (a, lifi) Pe Mossbauer absorption spectra of [ Fe/Co(phen)3](C104)2 as a function of temperature versus Co/Rh as source (which was kept at 295 K). (b, right) Time-integral Fe MossbauCT emission spectra of [ Co/Co(phen)3](004)2 source as a function of temperature... 

The ferric oxide, hematite, used in the present work was a high purity powder reagent with a BET surface area of 27 m2/g 30 mg was employed in each run. Some measurements were made on hematite calcined in air to see the effects of sintering the surface on the chemical structure of the adsorbed metal ions. The hematite samples were checked by Mossbauer absorption and powder X-ray diffraction measurements. The Mossbauer absorption spectra consisted of a magnetic sextet with no superparamagnetic component due to fine particles ( ). 

Figure 3. Mossbauer absorption spectra of aconitase at 4.2 K in zero field. (A) Dithionite reduced enzyme activated with 99.9% enriched Fe. (B) Dithionite reduced enzyme activated with >90% enriched Fe. (C) Apoaconitase incubated with dithionite and Fe. (Reproduced with permission from ref. 39. Copyright 1982 the authors.)...

Fig. 4. Mossbauer absorption spectra of hemoglobin fluoride at a) 4 °K, background 40%, and b) 1.2 °K, background 40%.

Fig. 6. 57Fe Mossbauer absorption spectra of [Fe(phen)2(NCS)2] as a function of temperature (P, Ganguli, P. Gutlich, W. MUller, unpublished)...

Fig 1. Fe Mossbauer absorption spectra measured for horse spleen ferritin measured at four temperatures relative to a room-temperature CoRh source. Reproduced from Ref 31. The solid lines represent computer fits to the experimental data. The average blocking temperature, Tb, for this ferritin is near 40 K and the calculated distribution of iron core diameters extends from 36 to nearly 90 A. with a maximum at 63 A. 

Fig. 2. Mossbauer absorption spectra of the BFR of Escherichia coli (grown on media enriched with Fe) measured at three temperatures relative to a CoRh source at room temperature. Reproduced from Ref. 33.

Fig. 4. Mossbauer absorption spectra obtained using a 57Co in Pd source at room temperature and ferritin as absorber at II °K, 86 °K and 293 °K (reproduced from (103))...

Fig. 6.15. Mossbauer absorption spectra in various biological systems containing Fe. The solid curves are theoretical least square fits. The parameters D (in units of 10" mVs) and a (in units of 10 s ) are respectivdy (a) 4, 2.5, (i) 40, 10, (c) 26, 5, and (d) 87, 13. (Nowik et a ., 1983.)...

Fig. 5.1 Fe Mossbauer absorption spectra for (a) a JR train ticket, and (b) a credit card (magnetic stripe part)...

Fig. 5.2 Mossbauer absorption spectra for Fe/Mg multilayers at 300 K (room temperature) and 4.2 K [5]. Sample structures (each thickness of Fe and Mg layers) are shown in the figure...

Fig. 5.6 RT Fe Mossbauer absorption spectra Fot Fe/Mn interfaces. Sample structures are illustrated in the figure, (a) and (b) show the situations of Mnon-Fe and Fe-on-Mn interfaces, respectively [24]...

Fig. 5.8 Fe Mossbauer absorption spectra for MgO-coated Fe surface at RT and 4 K. The peak positions of bulk a-Fe are indicated for comparison [25]...

The Mossbauer absorption spectra (22.5 keV-y transition in as source) at 4.2 K to room temperature indicate short range spin ordering below 14 K. This is consistent with the energy level scheme deduced from magnetic measurements. Best data fit was obtained by assumption of a hyperfine field of 54.6 kOe corresponding to a 1.2% polarization of the Tj moment [7]. 

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