Synthesis of Ni nanoparticles in lanthanum chromite ceramic matrix
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2016
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BRAZILIAN MRS MEETING, 15th
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Resumo
Lanthanum chromite is a well-known interconnector for solid oxide fuel cells. It
presents electronic conductivity at high temperatures. Moreover it is very stable
in oxidizing and reducing atmospheres. Due to its high stability this material is a
promising matrix to produce and stabilize nanoparticles by exothermal reaction.
The objective of the present work is to synthesize and stabilize nickel
nanoparticles in a stable ceramic matrix. Compounds of (La1-xSrx)a(Cr1-yNiy)O3 (x
and y = 0, 0.1, and 0.2; a = 1, and 0.8) were synthesized by Pechini method. The
powders were heat treated in air at 1300 °C and 1600°C in attempt to solubilize
NiO in the matrix. Then the samples were exposed to a reducing treatment in H2(g)
flux at 900°C per 8 hours. XRD measurements were made using a D8 Focus,
Bruker AXS. The data was acquired in a range of 2θ from 20° to 90°, with a step
of 0,02° per second. Magnetic properties were investigated utilizing a SQUIDVSM
from Quantum Design. Magnetic moment at constant magnetic field (100 Oe
and 1000 Oe) was measured in a range of 2K to 300K. Analyses with variable
magnetic field were performed at 2K, 196K and 390K in a rage from -5 up to 5 T.
Samples were observed using TEM technique. The XRD results showed that the
stoichiometric samples achieved desiderate phase. Compounds without Sr and
non-stoichiometric lanthanum site showed an incomplete nickel solid solution.
The addition of 10% of Sr decreases the Néel temperature from 289 K to 285K. Ni
doping created a stronger effect, lowering the temperature down to 267 K , in the
sample with 10% of dopant. After reduction is possible to observe peaks of Ni in
the XRD, indicating that nickel was exoluted form the matrix. Images of TEM
confirm the presence of nanoparticles with an approximate diameter of 3 nm. The
reducing treatment increased the magnetic response.
Como referenciar
TINTI, VICTOR B.; FONSECA, FABIO C.; FLORIO, DANIEL Z. de. Synthesis of Ni nanoparticles in lanthanum chromite ceramic matrix. In: BRAZILIAN MRS MEETING, 15th, September 25-29, 2016, Campinas, SP. Abstract... São Carlos, SP: Aptor Software, 2016. p. 657-657. Disponível em: http://repositorio.ipen.br/handle/123456789/28080. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.