Structural manipulation of pyrochlores: Thermal evolution of metastable Gd2(Ti1−yZry)2O7 powders prepared by mechanical milling

Increased stability of nanocrystals of Gd2(Ti0.65Zr0.35)2O7 pyrochlore at high pressure

“…Fig. 2 shows the typical morphology of the samples after heat treatment at 800 • C, 1000 • C, 1200 • C and 1500 • C for 12 h. The first two samples are typical nano-sized materials, and the average grain-size by TEM observation is <20 nm, which is in good agreement with the results of ex situ XRD analysis [18,19]. The only difference between the samples is the degree of ordering.…”

“…The samples of the Gd2(Ti0.65Zr0.35)2O7 pyrochlore were prepared by mechanical milling [18]. X-ray diffraction (XRD) measurements indicated that the as-milled samples are in disordered state-mixture of defect-fluorite structure and amorphous.…”

“…In order to get the samples with different grain-size, the samples were 0925-8388/$ -see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2010.01.036 subsequently thermal annealed at temperatures of 800 • C, 1000 • C, 1200 • C and 1500 • C for 12 h, respectively [18,19]. The structure of the samples was identified by XRD and Raman scattering measurements.…”

Sol–Gel Synthesis of Tunable Cerium Titanate Materials

“…[33,34] Furthermore, a band around 720 cm-1 increases in intensity with temperature. This vibrational mode could be assigned to seven-coordinate Ti atoms in a fluoritelike structure, [35] which indicates the incorporation of titanium ions into the fluorite ceria lattice. Once the structural evolution of the CeO 2 -TiO 2 mixed oxide system with temperature was established, the optical properties of the samples were investigated by UV-visible absorption and luminescence measurements.…”

Preparação de catalisadores de reforma de glicerol para células a combustível de eletrólito sólido

“…propriedades físicas e químicas: condutividade iônica-eletrônica, atividade catalítica e outros como, comportamento piezoelétrico, eletro-óptico e ferromagnetismo, dependendo da composição dos aditivos e da pressão parcial de oxigênio (MORENO, 2006).…”