Low-temperature sintering of BaTiO3 positive temperature coefficient of resistivity (PTCR) ceramics
| Autor: | Jörg Töpfer, Christian Teichmann |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Orders of magnitude (temperature) Sintering 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry.chemical_compound chemistry Electrical resistivity and conductivity visual_art 0103 physical sciences Barium titanate visual_art.visual_art_medium Curie temperature Ceramic Electrical and Electronic Engineering Composite material 0210 nano-technology Temperature coefficient |
| Zdroj: | Journal of Materials Science: Materials in Electronics. 29:17881-17886 |
| ISSN: | 1573-482X 0957-4522 |
| Popis: | Donor–acceptor-codoped and Ti-excess barium titanate ceramics BaTi1.007−x−yNbxMnyO3 with positive temperature coefficient of resistivity (PTCR) behavior were prepared via the mixed oxide route. Resistivity versus temperature characteristics of samples sintered in air at 1350 °C were investigated as a function of dopant concentrations. A low room-temperature resistivity ρRT = 80 Ωcm and large resistivity change ρmax/ρmin of four orders of magnitude at the Curie temperature was observed for x = 0.002 and y = 0.0003. To reduce the sintering temperature and enable low-temperature sintering of PTCR ceramics, several additives inducing liquid-phase sintering were tested. We report on the effect of BaB2O4 and LiF–SrCO3 additives on the sintering behavior, microstructure, and ρ(T) characteristics. It is shown by dilatometry that the sintering temperature is drastically reduced. PTCR ceramics with resistivity change ρmax/ρmin of two orders magnitude were obtained with addition of 3 wt% BaB2O4 and sintering at 950 °C, or with a combined addition of 3 wt% BaB2O4 and 0.25 wt% LiF–SrCO3 and sintering at 900 °C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink