resumo
The correlation between the microstructure and electrical properties of NiO-Ce0.9Gd0.1O1.95 (NiO-CGO) composites prepared by a one-step synthesis method is reported in the present work, and compared to conventional samples synthesized by mechanically mixing commercial powders. Samples sintered between 1350 and 1450 degrees C had their microstructures and electrical properties investigated by scanning electron microscopy (SEM) and impedance spectroscopy. The total electrical conductivity in the range of 100 -500 degrees C of one-step composites is more than one order of magnitude higher than for conventional material. This result is associated to the presence of a network of well-connected and homogeneously distributed NiO grains shown by SEM for the one-step composite, which is responsible for its improved percolative behavior and lower activation energy (0.24 eV at 250 - 650 degrees C).
palavras-chave
OXIDE FUEL-CELLS; ANODE MATERIALS; TRANSPORT; POWDERS
categoria
Electrochemistry; Science & Technology - Other Topics
autores
Macedo, DA; Figueiredo, FML; Patricio, SG; Nascimento, RM; Martinelli, AE; Paskocimas, CA; Marques, FMB
nossos autores
Fernando Manuel Bico Marques
Professor Catedrático
Filipe Miguel H Lebre R Figueiredo
Investigador Principal
Sónia Gonçalves Patrício
Investigador AuxiliarGrupos
3 - materiais de carbono, compósitos e revestimentos funcionais
5 - materiais biomédicos e biomiméticos
agradecimentos
The authors acknowledge PPGCEM UFRN, CAPES (PRO-ENGENHARIAS and PDEE program BEX 6775/10-1), CAPES-PROCAD, and FCT (Portugal) for the financial support. S. G. Patricio thanks FCT for the post-doctoral grant.