Structural properties of Al2O3-La2O3 binary oxides prepared by sol-gel
Por:
Barrera A., Fuentes S., Viniegra M., Avalos-Borja M., Bogdanchikova N., Campa-Molina J.
Publicada:
1 ene 2007
Resumen:
The structural properties of La2O3 and Al2O3-La2O3 binary oxides prepared by sol-gel were studied by XRD, HRTEM and UV-vis. The binary oxides with high lanthana contents show an amorphous structure after calcination at 650 °C. At calcination temperatures higher than 1000 °C there is a phase transformation from the amorphous state to the crystalline LaAlO3 with a perovskite structure. The structure of La2O3 is consistent with the hexagonal system; however, some crystalline microdomains with a monoclinic structure were detected by HRTEM. Islands of La2O3 and LaAl11O18 phases were detected at high lanthana concentration in the binary oxide. The modification in the coordination shell of the Al3+ cations due to the interaction with La3+ cations confirms the formation of phases with a perovskite structure and the presence of islands of the LaAl11O18 phase. © 2006 Elsevier Ltd. All rights reserved.
Filiaciones:
Barrera A.:
Universidad de Guadalajara, Centro Universitario de la Ciénega, Av. Universidad 1115, Col. Linda Vista, Ocotlan Jal., Mexico
Fuentes S.:
Centro de Ciencias de la Materia Condensada, UNAM, Ensenada, BC, Mexico
Viniegra M.:
Universidad Autónoma Metropolitana-Iztapalapa, México, D.F., Mexico
Avalos-Borja M.:
Centro de Ciencias de la Materia Condensada, UNAM, Ensenada, BC, Mexico
Bogdanchikova N.:
Centro de Ciencias de la Materia Condensada, UNAM, Ensenada, BC, Mexico
Campa-Molina J.:
Universidad de Guadalajara, Centro Universitario de la Ciénega, Av. Universidad 1115, Col. Linda Vista, Ocotlan Jal., Mexico
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