Effect of V2O5 doping on the microstructure and local composition of textured Sr0.4Ba0.6Nb2O6 ceramics
| Autor: | Hui Gu, Xian-Hao Wang, Li-Ping You, Qing-Wei Huang |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Doping Metals and Alloys Mineralogy Liquid phase Strontium barium niobate Condensed Matter Physics Microstructure Analytical electron microscopy chemistry.chemical_compound chemistry visual_art Powder metallurgy Materials Chemistry visual_art.visual_art_medium Grain boundary Ceramic Physical and Theoretical Chemistry Composite material |
| Zdroj: | International Journal of Materials Research. 98:228-234 |
| ISSN: | 2195-8556 1862-5282 |
| Popis: | A comparison of phases and the microstructures of textured Sr0.4Ba0.6Nb2O6 ceramics without and with V2O5 addition was carried out using transmission and analytical electron microscopy. The dopant was not found in Sr0.4Ba0.6Nb2O6 grains but in the inter-granular regions, including both grain boundary and second phase. Grain boundaries in the sample without V2O5 are clean, but those in the V2O5-doped sample exhibit a variety of structures, with and without an amorphous film of variable thickness. In general the vanadium excess follows the same trend of film width, while the Sr excess is generally negative and the Ba excess is positive, suggesting that the amorphous films at grain boundaries are rich in V and Ba and deficient in Nb and Sr. The second phase was determined as Ba3V4O13 phase containing small amounts of Sr and Nb. Such V- and Ba-rich inter-granular liquids promoted the densification and texturing, and affected the dielectric constant at low frequency but not the Curie temperature. |
| Databáze: | OpenAIRE |
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