Vibrational study of metal-substituted MPS3 layered compounds: MII1−xMI2xPS3 with MII = Mn, Cd, and MI = Cu (x = 0.13) or Ag (x = 0.50)

Abstract The infrared, polarized Raman, and inelastic neutron scattering spectra (650−10 cm −1 ) of M II 0.87 Cu I 0.26 PS 3 and M II 0.5 Ag I 1.0 PS 3 compounds, where M II = Mn, Cd, have been recorded and compared with those of the related M II PS 3 derivatives. It is shown that all these new metal-substituted systems maintain a bidimensional structure (CdCl 2 type) consisting of P 2 S 4− 6 entities, monometallic M II S 6 , and bimetallic ( M I ) 2 S 6 octahedra. The copper derivatives are disordered because of a random distribution of Cu 2 S 6 entities; meanwhile, the silver-containing lattices seem ordered. The vibrational modes assigned to translational motions of Cu I and Ag I cations have been clearly identified in the low-frequency region ( ν −1 ). Finally, the magnetic and vibrational properties of the Mn 0.87 Cu 0.26 PS 3 host lattice intercalated with Co(C 5 H 5 ) 2 + have been investigated; this definitely confirms the layered character of this new family of compounds.