Iron foil

Blech, n. plate, sheet, sheet metal, specif, slieet iron foil (weisses) tin plate (schwarzes) black iron plate, -aussetmitt, -ausstoss, m (Metal.) blank, -biichse, /. tin can, tin. -dose, /. tin box tin can, tin. -eisen, n. sheet iron. 

Method III was tested8 on silver and on zirconium as substrate metal covered with a plating built up of iron foil 0.6 mil (0.00152 cm) thick. The substrate metals were chosen because their Ka lines, although differing considerably in wavelength, can yet excite the K lines of iron. The use of foil made it easy to obtain plating thicknesses of high precision. 

In Equation 6-1, Io/I, usually an intensity ratio, is the quotient of the corrected average counting rate for the exposed substrate by that for the substrate covered with d cm of iron foil. The mass absorption coefficients of iron are m, a mean value for the incident (polychromatic) beam and g2, for the characteristic line being counted. The angles d and 02 are those made with the sample by the incident beam (30°) and by the emergent beam (60°), the beams being regarded as rays and... 

Fig. 3.23 Left-. Calculated relationship between the thickness of an alteration rind and/or dust coating on a rock and the amount of 15.0-keV radiation absorbed in the rind/coating for densities of 0.4, 2.4, and 4.0 g cm [57]. The bulk chemical composition of basaltic rock was used in the calculations, and the 15.0 keV energy is approximately the energy of the 14.4 keV y-ray used in the Mossbauer experiment. The stippled area between densities of 2.4 and 4.0 g cm is the region for dry bulk densities of terrestrial andesitic and basaltic rocks [58]. The stippled area between densities of 0.1 and 0.4 g cm approximates the range of densities possible for Martian dust. The density of 0.1 g cm is the density of basaltic dust deposited by air fall in laboratory experiments [59]. Right Measured spectra obtained on layered laboratory samples and the corresponding simulated spectra, from top to bottom 14.4 keV measured (m) 14.4 keV simulated (s) 6.4 keV measured (m) and 6.4 keV simulated (s). All measurements were performed at room temperature. Zero velocity is referenced with respect to metallic iron foil. Simulation was performed using a Monte Carlo-based program (see [56])...

Apart from the already mentioned (Sect. 7.6.1) determination of the nuclear g-factors of W through Mossbauer measurements with tungsten diluted in an iron foil [225, 229] where a hyperfine field at the W site of 70.8 2.5 T was... 

NFS Visualized by the Nuclear Lighthouse Effect (NLE) (Example Iron Foil)... 

The Fe K-edge spectra were recorded in the transmission mode and a metallic iron foil spectrum was measured simultaneously with each sample spectrum for energy calibration. X-ray absorption spectra for each sample were collected from 7,520 to 8,470 eV, with a step size of 0.40 eV and acquisition times of ca. 68 s per sample. Measuring each sample, in turn, and repeating... 

Figure 6 illustrates a more complicated situation. The sample was a plain iron-carbon steel—an iron foil carburized to about 5 atomic % carbon and then quenched. One sees a rather complex pattern. There is a large central peak from some untransformed high temperature face-centered phase of iron containing carbon in solid solution, retained austenite. There is a strong six-line pattern coming from martensite, a distorted body-centered solid solution of carbon in iron. We also see a... 

Present M sbauer Studies of Natural Pyroxenes and Olivines. Table IX gives the major element chemical compositions of the silicate minerals examined in this study. Table X compares the Mossbauer parameters of these minerals, while Figures 9-13 show representative Mossbauer spectra. Fayalite (Figure 9) is the only olivine in this group. The two lines are, however, somewhat broadened (0.35 and 0.39 mm./ sec.) compared with the width of natural iron foil lines observed with our source (0.24 mm./sec.) and suggest the near coincidence of two quadrupole-split doublets resulting from Mi and M2 sites. Analysis of this "two-line spectrum into a four-line spectrum in the manner described by Evans et al (11) could possibly yield parameters for the two iron sites, but this was not undertaken since both lines appear symmetric. The "two-line quadrupole splitting of 2.78 mm./sec. is somewhat smaller... 

All shifts are at room temperature in mm./sec. Zero velocity is defined with respect to the center of a natural iron foil absorber. Sodium nitroprusside has a shift of —0.26 mm./sec. on this scale. In Ref. IS a typographical error inadvertently gave this shift as —0.361 mm./sec. 

A similar correlation of 8 and A can be found in low spin ferric compounds, but it is studied with better advantage in the ferrous series, where the range of shifts is greater. The most positive shift in ferrous compounds consistent with fully low spin bonding appears to be in the range +0.4 +0.5 mm./sec. with respect to an iron foil absorber deflned... 

All shift are room temperature values in mm./sec. Zero is defined with respect to the center of a natural iron foil absorber. 

We close with a plea to investigators to report shift data with respect to a standard absorber, either clean iron foil or sodium nitroprusside or both. The logic behind this request is obvious since anyone who has tried to intercompare results between different papers, knows how frustrating it can be when no common substances were studied. We also suggest that inherently narrow line sources be used—i.e., Cu, Pt, Pd, or Cr. Stainless steel sources are usually so broad that they can often mask important features of the spectrum. Of the host matrices mentioned we prefer Cu since it doesn t give rise to any interfering x-rays and when prepared properly doesn t show any broadening at low temperatures. 

Another method is the conduction-electron polarization effect (CEP) discussed by Shirley and Westenbarger (35). deWaard and Drentje (37) have utilized this effect by driving atoms into a thin iron foil with... 

N. E. Erickson Regarding iron for calibration, some workers run in a time mode but use a sinusoidal drive. This results in an extremely nonlinear velocity scale, and a two-line pattern, such as in sodium nitro-prusside, is just not reasonable for a standard. One needs more lines, with a wider separation. I would like a standard which gives six lines, and hence I favor iron. Perhaps the Bureau of Standards, and I know I have spoken with you (Spijkerman) about this and you argue against it, could calibrate iron foils, which would provide a known six line spectrum. 

Thus, the diffusion layers in iron foils after nitriding consist of phases as follows ... 

The electrical resistance (ER) method to monitor physical changes in an electrically conducting material is well known(6). 10 cm x 2.5 cm coated iron foils of 10 micron thickness were electrically resistance monitored during exposure to various corrosive environments to follow metal thickness loss at the paint/metal interface. The circuit shown in Figure 1 allowed foil resistance increase AR, which is directly related to metal thickness loss Ad according to Equation (1), to be determined within 0.003 microns. 

The absolute velocity imparted to the drive shaft can be determined either directly or indirectly (30, 32, 87, 88). In the latter technique, the spectrum of a compound with well-established Mossbauer parameters is collected, and to the positions in the spectrum where resonances appear, specific absolute velocities can be assigned. The velocities at other positions in the spectrum are then inferred by interpolation between these known velocities. This indirect calibration is then used in the interpretation of other spectra obtained with the same drive unit. Unfortunately, compounds with well-established Mossbauer parameters may not be available for the Mossbauer isotope of interest. For 57Fe, however, this is not a problem, and metallic iron foils and sodium nitroprusside are often used for calibration purposes. Thus, the 57Fe resonance may be used to calibrate the drive unit, and this unit can then be used to study other Mossbauer isotopes if the drive unit is operated under identical conditions. 

Fig. 35. Mossbauer spectra of an iron foil after various oxidation times, (a) 3.2, (b) 15.5, (c) 30.9 hr. Reproduced from Channing and Graham (233) with permission from The Electrochemical Society.

The kinetics of a similar oxidation reaction was studied by Pritchard and Dobson (236). These authors studied the oxidation between 450 and 560 K of a metallic-iron foil (0.02 mm thick electroplated with 1 mg cm 2 57Fe) by deoxygenated water. The resulting Mossbauer spectra (at room temperature) showed Fe304 to be the only detectable reaction product, and from the ratio of the Fe304 spectral area to that of metallic iron, the magnetite film thickness y can be calculated. Assuming that the rate law is of the form... 

G. J. Fowler by heating ferrous chloride or bromide in ammonia. H. Hanemann used electrolytic iron foil A. H. White... 

Fig. 5.3 SEM analysis ofZn electrodeposits obtained at —0.12V where only UPD of Zn on Fe substrate occurs from pure 60.0—40.0 mol% [EMIM]+Cl /ZnCl2 ionic liquid, on to a 0.25 cm2 iron foil (a) sec-...

Figure 4.65 shows the 57Fe Mossbauer transmission spectra of thin iron foils oxidized with nitric oxide (NO) at 500°C and 600°C [146], In the spectra, the lines corresponding to the position of the Mossbauer transmission spectra of Fe, Fe203, and Fe304 are indicated. 

When electrolytic iron foil is heated in steam to about 330° C., tarnishing begins to take place. At 400° C. a small but measurable quantity of hydrogen is formed, and the velocity of the reaction increases rapidly with further rise of temperature The reaction appears to take place m three stages, involving2... 

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