Magnetic X-ray scattering

Fig. 39. Integrated intensity versus temperature for the (0,0,3) magnetic Bragg peak in URujSij as determined by resonant magnetic X-ray scattering. The solid line is a guide to the eye. Saturation corresponds to 8counts/s at the Bragg peak. (From Isaaes ct al. 1990.)...

Ch. Brouder, and M. Hikam. Multiple scattering theory of magnetic x-ray circular dichroism. Phys. Rev. 

The Maxwell theory of X-ray scattering by stable systems, both solids and liquids, is described in many textbooks. A simple and compact presentation is given in Chapter 15 of Electrodynamics of Continuous Media [20]. The incident electric and magnetic X-ray helds are plane waves Ex(r, f) = Exo exp[i(q r — fixO] H(r, t) = H o exp[/(q r — fixO] with a spatially and temporally constant amplitude. The electric field Ex(r, t) induces a forced oscillation of the electrons in the body. They then act as elementary antennas emitting the scattered X-ray radiation. For many purposes, the electrons may be considered to be free. One then finds that the intensity /x(q) of the X-ray radiation scattered along the wavevector q is... 

Water on Smectites. Compared to vermiculites, smectites present a more difficult experimental system because of the lack of stacking order of the layers. For these materials, the traditional technique of X-ray diffraction, either using the Bragg or non-Bragg intensities, is of little use. Spectroscopic techniques, especially nuclear magnetic resonance and infrared, as well as neutron and X-ray scattering have provided detailed information about the position of the water molecules, the dynamics of the water molecule motions, and the coordination about the interlayer cations. 

The Maxwell theory of X-ray scattering by stable systems, both solids and liquids, is described in many textbooks. A simple and compact presentation is given in Chapter 15 of the Landau-Lifshitz volume. Electrodynamics of Continuous Media [20]. The incident electric and magnetic X-ray fields are plane waves... 

For the X-ray scattering observations the samples were powdered and placed in Lindemann glass capillary tubes. The capillaries were held for 8 weeks at 293 K in closed containers in contact either with hexane vapour or with aqueous salt solutions of different relative humidity. At the end of the preparation, the capillary tubes were flame-sealed. X-ray measurements were made at the BM2 bending magnet beam line at the ESRF, Grenoble, France. With incident energy 18 keV, the wave vector range explored was 6x 10 [Pg.44]

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