Preparation and Characterization of Lanthanum Silicon-Nitride
Lanthanum silicon nitride (LaSi3N5) powder has been prepared under the relatively mild conditions of 1400 ° C and 1 atm nitrogen. Chemical, X-ray diffraction, solid state nuclear magnetic resonance spectra and morphological information on this powder is presented. The X-ray diffraction data and previously published information have been used to develop a more complete specification of the unit cell dimensions.29Si magic-angle spinning nuclear magnetic resonance spectra of LaSi3N5 show two chemical shifts at ?64.5 and ?56.5 p.p.m. These shifts reflect two electronically different “types” of silicon which have been attributed to the effects of quadrupolar139La nuclei and their spatial arrangements around silicon atoms.