Controlling interface characteristics by adjusting core–shell structure
| Autor: | Ching-Iuan Sheu, Horng-Yi Chang, S.Y. Cheng |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Materials science
Polymers and Plastics Annealing (metallurgy) Reducing atmosphere Metals and Alloys Oxide Mineralogy chemistry.chemical_element Titanate Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry visual_art Ceramics and Composites visual_art.visual_art_medium Strontium titanate Grain boundary Ceramic Composite material Titanium |
| Zdroj: | Acta Materialia. 52:5389-5396 |
| ISSN: | 1359-6454 |
| DOI: | 10.1016/j.actamat.2004.07.047 |
| Popis: | Most grain boundary layer ceramics comprise semiconductive/conductive grains and insulated grain boundaries. Such a structure can be theoretically regarded as a shell (grain boundary layer) surrounds a core (conductive or semiconductive grain). The core-shell structure of titanium (Ti)-strontium titanate (ST) is composed of three zones - ST, non-stoichiometric strontium-titanium oxide and Ti, in order from shell to core. It was successfully prepared using a hydrothermal method. The Ti-ST core-shell structure was sintered in a reducing atmosphere and then annealed in air to achieve the metal-insulator-metal structure (MIM structure). The resulting MIM structure, annealed in air, changes with the oxygen stoichiometry of the ST shell (insulator layer) at various temperatures, which is thus used to tune its electrical characteristics. The characteristics exhibit nonlinear behavior. Accordingly, the thickness of the insulator layer can be adjusted in various annealing atmospheres and at various temperatures to develop various interfacial devices, such as varistors, capacitors and thermistors, without the use of complex donor/acceptor doping technology. |
| Databáze: | OpenAIRE |
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