Transport and Structural Properties of Pure and Cr Doped Li₃VO₄

Abstract

This study deals with the effects of 5 and 10% chromium additions on the transport and structural properties of Li3VO4. The Cr substitution is easily obtained without impurity phases and does not affect the room- and high-temperature host crystal structure, as evidenced by X-ray powder diffraction and micro-Raman analysis. The EPR signals are interpreted in terms of quantified amounts of Cr ions in 5+ and 3+ valence states. Suitable 7Li and 51V MAS NMR spectra simulations agree with the EPR results about the relative amount of Cr5+ and Cr3+ ions substituted in V5+ and Li+ sites, respectively. The Cr3+ presence on Li site, also suggested by Raman results and Rietveld refinements, requires Li vacancies to maintain the charge neutrality. The p-type conductivity, suggested by the positive thermoelectric power coefficients, significantly increases by the cation doping up to an order of magnitude.

Intercalation assembly of Li3VO4 nanoribbons/graphene sandwich-structured composites with enhanced oxygen reduction catalytic performance

“…1 38-1247) with few peaks belonging to small amount of LiVO 3 phase (JCPDS no. which was also reported in previous works by different methods [55,56].…”

Solid state NMR spectroscopy

“…99 High-field 139 La NMR spectra were used to follow the phase behaviour for phase-separated La 1Àx Sr xCoO 3 . 100 A 17 O NMR study has been made of the inhomogeneous electronic states of crystalline La 2Àx Sr x CuO 4 , where x = 0.035, 0.05, 0.07, 0.115, 0.15. 101 Highresolution 15 N, 17 O, 27 Al and 29 Si MAS NMR spectra of La 3 Si 3 Al 3 O 12 N 2 gave information on the glass to crystal transition, and revealed (Si, Al) and (O, N) disorder.…”

“…100 A 17 O NMR study has been made of the inhomogeneous electronic states of crystalline La 2Àx Sr x CuO 4 , where x = 0.035, 0.05, 0.07, 0.115, 0.15. 101 Highresolution 15 N, 17 O, 27 Al and 29 Si MAS NMR spectra of La 3 Si 3 Al 3 O 12 N 2 gave information on the glass to crystal transition, and revealed (Si, Al) and (O, N) disorder. 102 31 P solid-state NMR was used to characterise the lanthanide phosphate nanocrystals LnPO 4 Á xH 2 O, where Ln = Ce, Tb or Eu; x B 0.7.…”

“…115 A 195 Pt NMR study was reported for the superconductor UPt 3 . 116 A theoretical analysis has been carried out on 17 O NMR parameters for NpO 2 . 117 An experimental 17 O NMR study of NpO 2 at temperatures below 26 K showed the presence of two inequivalent oxygen sites.…”

“…116 A theoretical analysis has been carried out on 17 O NMR parameters for NpO 2 . 117 An experimental 17 O NMR study of NpO 2 at temperatures below 26 K showed the presence of two inequivalent oxygen sites. 118 238,239 Pu MAS NMR spectra were reported for highly-radioactive ceramic samples containing 5-10% Pu.…”