Artigo de peri??dico
Electrical behavior of electric field-assisted pressureless sintered ceria-20 mol% samaria
Registro en:
2571-6131
2
2
10.3390/ceramics2020030
0000-0002-8598-279X
0000-0001-9219-388X
Sem Percentil
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Autor
REIS, SHIRLEY L.
CARVALHO, SABRINA G.M.
MUCCILLO, ELIANA N.S.
MUCCILLO, REGINALDO
Resumen
CeO2:20 mol% Sm2O3 green ceramic pellets were sintered conventionally at 1500 C/2
h and flash sintered by applying a 200 V cm????1 electric field at 800 C, 1000 C and 1200 C. The
thickness shrinkage of the pellets was followed bythe specimen being positioned inside a dilatometer
adapted with platinum electrodes and terminal leads connected to a power supply for application
of the electric voltage. The microstructure of the surfaces of the sintered samples were observed
in a scanning electron microscope. The electrical properties were evaluated by the impedance
spectroscopy technique in the 5 Hz???13 MHz frequency range from 210 C to 280 C. The main results
show that (i) the final shrinkage level is nearly independent of the temperature when the electric field
is applied and slightly better than that of the 1500 C sintered pellet, and (ii) the bulk conductivity of
the sample flash sintered at 1200 C is similar to that of the sample sintered at 1500 C. The availability
of a pathway for the electric current pulse derived from the applied electric field is proposed as the
reason for the achieved shrinkages. Scavenging of the grain boundaries by Joule heating is proposed
as the reason for the improved oxide ion bulk conductivity. Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) CNPq: 302357/2018-1; 305889/2018-4; 150101/2017-1 FAPESP: 13/07296-2; 17/11937-4