A Novel Chemical Route to Prepare La₂Zr₂O₇ Pyrochlore

Abstract

Lanthanum zirconate has been prepared via a new chemical synthesis method by combining sol-gel processing and complex precipitation. The synthesis was carried out in aqueous solution under ambient conditions. The synthesized powder possessed the pyrochlore superstructure upon calcination above 1200°C. A suite of characterization techniques, including FTIR, Raman, X-ray and electron diffraction, TEM, SEM, and nitrogen sorption were employed to investigate the microstructural evolution and bulk properties. Dense ceramics (>90% relative density) were obtained after sintering at 1400°C, without need for additional processing (i.e., hot or cold isostatic pressing) or any milling steps. A mechanism has been proposed that elucidates molecular assembly of this chemical synthesis method.

Structural evolution and thermal conductivities of (Gd1−xYbx)2Zr2O7 (x=0, 0.02, 0.04, 0.06, 0.08, 0.1) ceramics for thermal barrier coatings

“…Several major Raman modes corresponding to the pyrochlore structure are clearly evident in (Gd 1-x Yb x ) 2 Zr 2 O 7 (x = 0, 0.02, 0.04, 0.06), they are the A 1g mode at ~ 520 cm -1 , the E g mode at ~ 310 cm -1 , and the F 2g modes at ~ 400 cm -1 and 595 cm -1 . Two additional F 2g modes at around 710 cm -1 and 780 cm -1 are indistinguishable from background, which is consistent with the literatures [22,19]. In these compounds, the Raman bands become broader as Yb 2 O 3 content increasing, which is believed to stem from structural disorder [23,24].…”

An electron spin resonance and photoluminescence investigation of the effect of annealing temperature on Gd-doped La2Zr2O7 nano-ceramics

“…Moreover, in case of samples prepared via co-precipitation route, the final is often a mixture of different metal hydroxides due to the variation of precipitation rates of different cations [26]. Kong et al have reported a novel sol-gel route for the preparation of LZO pyrochlores with better homogeneity and uniform density [27]. The authors were successful in synthesizing the final product with more than 490% relative density when sintered at 1400 1C.…”

Fabrication and phase transition of Gd2Zr2O7 ceramics immobilized various simulated radionuclides

“…Gadolinium zirconate (Gd 2 Zr 2 O 7 ) has attracted significant interest as a potential host material for the immobilization of radioactive waste due to its high thermal stability, high chemical resistance and durability [1][2][3]. Furthermore, the oxides structure can incorporate large amounts of actinides within both of its cation sites [4,5].…”