The diffuse reflectance UV spectra of dehydrated titanium silicalites of MFI structure are consistent with the presence of both open [Ti(OH)(OSi)3] and closed [Ti(OS&] tetrahedral titanium sites, the closed sites seem to be the only ones occurring in Ti02-Si02 silica gel.
As a first step of a study of the electronic properties of C u 0 2 planes by probing calcium nuclei in the bismuth-based high-Tc materials we report here the structural assignment of Ca N M R lines measured in 43Ca-enriched samples of n = 2 ((Bi,Pb)2Sr2CaCu2O g+x) and n = 3 ((Bi,Pb)2Sr2-Ca2C u 3O 10+Jl.) bismuth compounds. Powdered samples were investigated as well as oriented pow ders, achieved by uniaxial alignment of the grains in a 7T magnetic field. For the main calcium site (Ca between two C u 0 2 planes), we could determine the quadrupolar as well as the shift tensors. The results indicate that, in the same way as yttrium nuclei in YBaCuO, calcium nuclei are sensitive to the magnetic susceptibility of the metallic C u 0 2 planes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.