Nano–Nano Composite Powders of Lanthanum Zirconate and Yttria‐Stabilized Zirconia by Spray Pyrolysis

Abstract

Powders composing of La2Zr2O7 (LZ) and (Zr0.8Y0.2)O1.9 (10YSZ) phases (volume ratio = 1:1) were synthesized by using a sol‐spray pyrolysis method. The effects of annealing temperature on the grain size and lattice parameter of the LZ–10YSZ powders were investigated. XRD results showed that the grain size of LZ and 10YSZ phases gradually grew from 10 to 95 nm and from 5 to 65 nm as the annealing temperature elevated from 900°C to 1200°C. The relative decreasing percentage of grain size comparing to that of the single‐phase LZ and 10YSZ powders were in the range 9%–36% and 37%–86%. The activation energy for grain growth of LZ and 10YSZ phases in the composite powders were 225 ± 12 and 382 ± 17 kJ/mol, which were 20% and 183% higher than that of the single‐phase counterparts. Obvious lattice contraction and lattice expansion for LZ and 10YSZ phases were observed at temperatures below 1100°C, respectively. SEM results revealed that LZ and 10YSZ phases were homogeneously distributed in the sintered bulk. The TEM results suggested that the grain growth was affected by the interaction on nanometer length scales of grain boundaries between LZ and 10YSZ phases in the composite.

Aging effect on microstructure and property of strontium zirconate coating co‐doped with double rare‐earth oxides

“…The La 2 (Zr 0.7 Ce 0.3 ) 2 O 7 composite has good sintering resistance and low thermal conductivity in comparison to La 2 Zr 2 O 7 and La 2 Ce 2 O 7 . The La 2 Zr 2 O 7 /YSZ nanocomposite powder has much higher activation energy for grain growth of La 2 Zr 2 O 7 and YSZ than that of the single‐phase counterparts, therefore in turn possessing higher phase stability and sintering resistance.…”

Effect of High‐Temperature Aging on the Fracture Toughness of 40 mol% Ceria‐Stabilized Zirconia

“…The powders with a composition of Zr 0.6 Ce 0.4 O 2 were synthesized by the sol‐spray pyrolysis method starting from Zr(NO 3 ) 4 ·3H 2 O and Ce(NO 3 ) 3 ·6H 2 O (99.99% purity, Aladdin Chemistry Co. Ltd., Shanghai, China) as described elsewhere . The obtained powders were annealed at 800°C–1200°C for 6 h in high‐purity Al 2 O 3 crucibles.…”

Catalytic Effect of CeO2‐Stabilized ZrO2 Ceramics with Strong Shock‐Heated Mono‐ and Di‐Atomic Gases

“…TBC with low thermal conductivity materials have been developed using mixed oxide like ZrO 2 –GdO 1.5 system . Double ceramic layer coating with low thermal conductivity and high phase stability has been developed using lanthanum‐based (Zr 10.5 x Ce x ) 2 O 7 system and YSZ composite powder with the addition of Ti is used for TBC . Many compounds are synthesized by dispersion of small percentage of metal/metal oxides on the surface of the ceria–zirconia materials.…”

“…3 Double ceramic layer coating with low thermal conductivity and high phase stability has been developed using lanthanum-based (Zr 10.5x Ce x ) 2 O 7 system 4 and YSZ composite powder with the addition of Ti is used for TBC. 5,6 Many compounds are synthesized by dispersion of small percentage of metal/metal oxides on the surface of the ceria-zirconia materials. Catalysts like Pt/CeZrO 2 /Al 2 O 3 , 7 ionically dispersed Pt over CeO 2 , 8 and combustion synthesized Rh/CeO 2 catalyst 9 for CO oxidation have been reported in the literature.…”