| Autor: |
Lucca Sánchez, Felipe Antonio, Tarragó, Diego Pereira, Takimi, A.S., Sousa, V.C., Bergmann, C.P. |
| Zdroj: |
Materials Science Forum; August 2012, Vol. 727 Issue: 1 p533-538, 6p |
| Abstrakt: |
t is well known that nanostructured materials have relevant influences in properties behavior that can be achieved when compared with conventional materials. In this study is proposed an investigation of the electrical and microstructural properties of zinc oxide based varistors prepared with nanostructured zinc oxide powder obtained by a thermal evaporation process. Zinc oxide powder morphology was investigated by scanning and transmission electron microscopy (SEM and TEM, respectively) and the specific surface area evaluated by adsorption of N2. The varistors were prepared by the mixture of typical dopants with zinc oxide powders in a ball mill. The surface area of zinc oxide powder used was 17.4 m2/g with tetra-needle like morphology. After powder mixture process it was observed by TEM micrographs that most of the tetrapod shaped zinc oxide broke into needles well mixed with dopant particles. The compressed powders were sintering at 1050, 1150 and 1250ºC for 1.5 h and densification over 94% were achieved in all tested temperatures. Preliminary electrical characterization reveals that nanostructured zinc oxide compositions have interesting varistor properties. |
| Databáze: |
Supplemental Index |
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