NMR studies of chalcogenide glasses: The system phosphorus-selenium

Abstract

The feasibility of modern pulsed high-field high resolution solid state NMR techniques in non-oxide chalcogenide glasses is demonstrated for the system phosphorus-selenium. Isotropic and anisotropic chemical shieldings as well as 31P-31P dipolar couplings from 31P MAS and spin-echo NMR are reported on the glasses (10 to 50 mole% P), and the crystalline model compounds P4Se3 and P4Se4. Measurement of spin-echo decays show a monotonic increase of 31P-31P homonuclear dipole-dipole couplings with increasing phosphorus contents. The latter result suggests that the structure is more random than implied by the cluster model previously suggested.