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ICAME 2007: Proceedings of the 29th International Conference by N.S. Gajbhiye, S. K. Date

By N.S. Gajbhiye, S. K. Date

Disordered nature of structural association in amorphous and nanocrystalline alloys provides upward thrust to effective gentle magnetic homes particularly from a realistic program standpoint [1]. in particular nanocrystalline alloys allure loads of scienti?c curiosity simply because, opposite to their amorphous opposite numbers, their magnetic parameters don't considerably become worse at increased temperatures in the course of the technique of their functional exploitation. To bene?t from their exact magnetic pr- erties, the mechanism of crystallization will be identified. right here, we current the examine of structural transformation of NANOPERM-type alloys through assistance from Mössbauer spectrometry, traditional X-ray diffraction (XRD), and by way of a complicated diffraction of synchrotron radiation. 2 Experimental Alloys of the composition Fe Mo Cu B for x = 12, 15, 17, 20 ready by way of 91?x eight 1 x fifty seven quick quenching on a rotating wheel have been analyzed within the as-cast nation through Fe transmission Mössbauer spectrometry (TMS) and through conversion electron Mössbauer spectrometry (CEMS). The acquired as-quenched ribbons have been approximately 10 mm huge and 20 ?m thick. The nanocrystalline nation used to be accomplished through annealing approximately 2 cm ? lengthy samples for 1 h at temperatures as much as 650 C in a vacuum. traditional XRD used to be played with Cu-K radiation in Bragg-Brentano con?guration with graphite ? monochromator within the diffracted beam. Monochromatic synchrotron radiation of 7keV(? = zero. 178 nm) supplied on the KMC-2 beamline at BESSY Berlin was once used for in situ examinations of structural ameliorations in the course of non-stop warmth therapy.

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Extra resources for ICAME 2007: Proceedings of the 29th International Conference on the Applications of the Mössbauer Effect (ICAME 2007) held in Kanpur, India, 14-19 October 2007

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Samples 29 300 0C 3 2 1 200 0C 3 2 1 0 pristine 2 4 6 θ (mrad) 8 10 using (4) which in the case of one-dimensional diffusion, is related to diffusivity D(T) through the relation L2d = 2D(T)t. 7 × 10−22 m2 /s respectively. These values are well below the grain boundary diffusion in polycrystalline Fe [18], however are comparable to diffusivity in nanocrystalline FeZr [19], where diffusion occurs mainly through grain boundaries which are amorphous in nature. These results demonstrate that nuclear resonance reflectivity from isotopic marker layers under standing wave conditions can be used to study self-diffusion with an accuracy which is roughly an order of magnitude better than that obtainable using conventional techniques like SIMS.

X-rays diffraction shows that the film is amorphous in nature. ID22N beamline of ESRF was used for measuring both electronic and nuclear pats of the reflectivity. The storage ring operated in 16-bunch mode providing short pulses of x rays (duration ∼100 ps) every 176 ns. The radiation from the undulator source, optimized for the 14,413 eV transition in 57 Fe, was filtered by a double Si (111) reflection followed by a high-resolution nested monochromator, providing a bandpass of 4 meV [12]. The scattered radiation was detected using fast avalanche photodiodes (time resolution ∼1 ns).

The values of these parameters are the same, within the errors. This result strongly suggests that iron in SN is bound mainly to ferritin. 0005 Relative Counting Rate Fig. 1 K from a fresh frozen sample of SN J. 9995 -10 -8 -6 -4 -2 0 2 4 6 8 10 Velocity (mm/s) The comparison of the concentration of iron in control and parkinsonian SNs did not show any difference. The first comparison was made on eight control SNs and six parkinsonian SNs [2]. The average concentration of iron in control tissue was 163 ± 12 ng/mg and for pathological tissue 159 ± 13 ng/mg.

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