Differential x ray

TEM and differential X-ray line broadening (expressed by the ratio of the width at half height of the 104 relative to that of the 110 reflection) indicate that the thickness of the platy Al-hematite crystals decreases as Al/(Fe-t Al) increases (Schwertmann et al., 1977 Barron et al., 1984). It is this change in morphology, rather than the structural Al, which governs the IR spectra, in particular the shape factor and the absorp-... 

Campbell, A.S. Schwertmann, U. (1985) Evaluation of selective dissolution extractants in soil chemistry and mineralogy by differential X-ray diffraction. Clay Min. 20 515-519 Campbell, A.S. Schwertmann, U. Campbell, P.A. (1993) Thermal analysis of ferrihydrite. 10 Int. Clay Conference, Adelaide, S.A., July 1993, Abstract, p. 0-26... 

Schulze, D.G. (1982) The identification of iron oxides by differential X-ray diffraction and the influence of aluminum substitution on the structure of goethite. Dissertation, Techn. Univ. Miinchen, Freising-Weihenstephan, Germany. University Microfilms Int., Ann Arbor, Michigan... 

Schwertmarm, U. Schulze, D.G. Murad, E. (1982) Identification of ferrihydrite in soils by dissolution kinetics, differential X-ray diffraction and Mossbauer spectroscopy. Soil Sd. Soc. Am. J. 46 869-875... 

Fundamentals. The scattered X-ray from crystal planes or a thin metal film can interfere coherently with scattered X-rays from an adsorbate layer. This phenomenon is called surface differential X-ray diffraction (SDD) or Bragg peak interference. The theory has been described elsewhere in detail [43,44], Information on the relative amount of material in the adsorbate layer (coverage) and the distance between atoms in the top layer of the substrate and in the adsorbate layer as a function of electrode potential can be derived from SDD measurements. 

U. Schwertmann and R. M. Taylor, Iron oxides, in Minerals in Soil Environments (J. B. Dixon and S. B. Weed, eds.) Soil Science Society of America, Madison, Wis., 1977. U. Schwertmann, D. G. Schulze, and E. Murad, Identification of ferrihydrite in soils by dissolution kinetics, differential X-ray diffraction, and Mossbauer spectroscopy, Soil Sci. Soc. Am. J. 46 869 (1982). 

Schulze, D. G. 1986. Correction of mismatches in 20 scales during differential X-ray diffraction. Clays and Clay Minerals 34, no. 6 681-685. doi 10.1346/CCMN.1986.0340610. 

FIGURE9.14 Comparison of calculated (a) and experimental (b) X-ray diffraction patterns for manganese minerals. Top patters birnessite, calculated and natural from Quebec middle todorokite, calculated and natural from Cuba bottom lithioporite, calculated and from soil nodules. Note the broad peaks in the actual patterns, indicating small crystals. In the case of lithiophorite, the actual pattern was obtained using a subtraction procedure (differential X-ray diffraction). (Reprinted from Dixon, J. B. and White, G. N., Soil Mineralogy with Environmental Applications, Soil Science Society of America, Madison, WI, 367-388, 2002, with kind permission.)... 

A.S. Campbell, U. Schwertmaim, Evaluation of selective dissolution extractants in soil chemistry and mineralogy by differential X-ray diffractioiL Clay Miner. 20,515—519 (1985)... 

The surface molecular motion of amorphous polymeric solids was measured by lateral force microscopy, scatming viscoelasticity microscopy, and differential X-ray photoelectron spectroscopy. Data are given for PS and styrene-methyl methacrylate copolymers. 35 refs. 

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