Application of Neutron Scattering in Earth Sciences

Characterization of Real Catalytic Materials

“…The same structure analysis technique may be performed using neutrons. 11 In this case, the position of protons may also be detected. Recent applications of neutron diffraction techniques with Rietveld analyses have been reported concerning the determination of the structure of gallium oxides and hydroxides 12 and the evolution of hydrotalcite structure (MgeAl layered hydroxyl-carbonate) upon calcination.…”

“…NMR techniques may be applied to any nucleus having nuclear spin >0. Thus, this technique may be applied not only to 1 H (S ¼ ½), but also to 2 H (S ¼ 1), 11 To avoid line broadening in the solid state, the samples must spin about an axis inclined at 54 44 0 ("magic angle") which is the q value at which 3 cos 2 q À 1 ¼ 0. Magic Angle Spinning (MAS) NMR studies of 27 Al (which is largely the most abundant Al isotope, 99.9%) and 29 Si (which is only 4.67% of natural silicon) that can be applied are very important for the characterization of aluminas, silicas, silica-aluminas, silicates and aluminosilicates including zeolites.…”