Structural and mechanical properties of La0.6Sr0.4M0.1Fe0.9O3-δ (M: Co, Ni and Cu) perovskites

La0.6Sr0.4M0.1Fe0.9O3-δ (M: Co, Ni and Cu) perovskite nanostructures were synthesized using low frequency ultrasound assisted synthesis technique and effect of substitution of Fe by Co, Ni and Cu on crystal structure and mechanical properties in La0.6Sr0.4FeO3-δ perovskite were studied. The HRTEM and Rietveld refinement analyses revealed the uniform equi-axial shape of the obtained nanostructures with the existence of La0.6Sr0.4M0.1Fe0.9O3−δ with mixed rhombohedral and orthorhombic structures. Substitution of Cu decreases the melting point of La0.6Sr0.4FeO3-δ. The results of mechanical characterizations show that La0.6Sr0.4Co0.1Fe0.9O3−δ and La0.6Sr0.4Ni0.1Fe0.9O3−δ have ferroelastic behavior and comparable elastic moduli, however, subtitution of Ni shows higher hardness and lower fracture toughness than Co in Bsite dopin

Effect of rare earth dopants on structural and mechanical properties of nanoceria synthesized by combustion method

Structural characteristics of combustion synthesized, calcined and densified pure and doped nanoceria with tri-valent cations of Er, Y, Gd, Sm and Nd were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that the as-synthesized and calcined nanopowders were mesoporous and calculated lattice parameters were close to theoretical ion-packing model. The effect of dopants on elastic modulus, microhardness and fracture toughness of sintered pure and doped ceria were investigated. It was observed that tri-valent cation dopants increased the hardness of the ceria, whereas the fracture toughness and elastic modulus were decreased

Preparation of nanosized yttrium doped CeO2 catalyst used for photocatalytic application

In the present work, the pure CeO2 and yttrium doped CeO2 nanopowders were synthesized by the nitrate-fuel self-sustaining combustion method and calcined at 700 C for 2 h. X-ray diffraction (XRD) and high resolution electron transmission microscopy (HRTEM) results demonstrated a cubic fluorite with high purity and the crystallite sizes less than 20 nm calculated from Scherrer’s formula. The BET specific surface area of yttrium doped CeO2 samples showed high values than those of pure CeO2. The photocatalytic activity of yttrium doped CeO2 showed high degradation of Rhodamine B solution under visible light illumination

Mechanical properties of Gd-CeO2 electrolyte for SOFC prepared by aqueous tape casting

Mechanical properties of gadolinium-doped ceria (Ce0.9Gd0.1O1.95, 10GDC) green tape prepared by aqueous-based tape casting process were characterized by tensile test and shear punch test (SPT). SPT was found to be a useful method for characterizing mechanical properties of green tapes. Microstructures and mechanical properties such as flexural modulus, bending strength, and microhardness of tapes sintered at 1,300–1,500 °C have been evaluated. Indentation fracture toughness was also determined by the method of Palmqvist cracks at different applied loads for tapes sintered at 1,500 °C. Grain size measurements showed that excessive grain growth occurred during sintering despite using 10GDC nanopowders as the starting material. However, mechanical properties of sintered tapes improved by increasing sintering temperature and the results are comparable with those reported for 10GDC in literature