If the relative stoichiometry of heavier elements in a material is known, fixing it in the standard Vesuvio data-analysis procedures enables a determination of neutron Compton widths. Measurements were conducted on three systems: bulk NaH, amorphous Na within a silica gel framework (SiGNa), and a system with both amorphous Na and NaH nanocrystallites encapsulated in the framework (SiGNaH). In addition to subtle differences in the proton momentum distribution in NaH and SiGNaH, a systematic increase in Na Compton widths is demonstrated in SiGNa, SiGNaH and bulk NaH. This sensitivity to chemical environment is further supported by examination of O and Si widths in the gel samples.
AG Seel, A Sartbaeva, PP Edwards (University of Oxford), J Mayers, AJ Ramirez-Cuesta (ISIS)
Research date: August 2011
Contact: Prof. PP Edwards, firstname.lastname@example.org
Further reading: AG Seel et al., J. Chem. Phys. 134 (2011) 114511