Nuclear magnetic resonance and differential thermal analysis studies of hydrogen molybdenum bronzes, HxMoO3

Abstract

NMR and DTA studies were carried out on four phases of hydrogen molybdenum bronzes, types I–IV. From DTA and X-ray data it is confirmed that the bronze with the highest hydrogen content changes successively to that with lowest hydrogen content and finally to MoO₃, by evolution of H₂. NMR spectra of types II–IV obtained in the present study can be clearly resolved into three components, a Pake doublet, a Gaussian and a Lorentzian, which are attributed to paired protons, isolated protons fixed on a site, and moving protons, respectively. The phase changes of the bronzes are discussed by connecting them with hydrogen insertion. A preliminary result of computer-simulation analyses of the lineshapes is also given.