INVESTIGADORES
ALDAO celso Manuel
artículos
Título:
Cobalt Oxide and Antimony Oxide Effects in the Zinc Oxide-Bismuth Oxide System
Autor/es:
M.S. CASTRO; C.M. ALDAO; J.M. PORTO LÓPEZ
Revista:
MATERIALS RESEARCH BULLETIN
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 1994 vol. 29 p. 1287 - 1295
ISSN:
0025-5408
Resumen:
process have been studied by several researchers. However,
some aspects of their influence on ZnO-BizO 3 sintering
behavior, which are important for the characteristics of
ZnO varistors, such as the phase distribution, are still
not well understood. Aiming to a better comprehension of
the involved phenomena, we have studied the thermal and
physicochemical behavior of the ZnO-BizO 3 system during the
sintering process (crystalline phases formed, evaporation
and decomposition reactions), by thermogravimetric
analysis, scanning electron microscopy and X-ray
diffraction. Thermogravimetric analysis shows a weight loss
of the samples during the sintering process. We show that
this weight loss is a consequence of Bi203 evaporation.
Experimental results indicate that the pyrochlore phase
restrains the bismuth oxide evaporation. At temperatures
higher than 950°C the pyrochlore reacts with ZnO and then
the weight loss and the grain growth rate increase.
