Tohoku Univ. Technology: Low temperature sintering of BaTiO3 using sodium vapor: T25-003
PTC thermistors can be fabricated in a simple and cost-effective manner.
Some semiconducting ferroelectric ceramics exhibit positive temperature coefficient (PTC) thermistor behavior, in which their electrical resistivity increases drastically above the Curie temperature. Materials based on perovskite-type barium titanate (BaTiO₃) are widely used as circuit protection devices under conditions of high temperature or large current surges. Conventional methods to change originally insulating BaTiO₃ powders to semiconductor require highly reducing atmospheres and high sintering temperatures near 1400 ℃. This invention proposes a low-temperature and cost-effective fabrication method for BaTiO₃-based semiconducting ceramics using sodium (Na) vapor. Grain size control in ceramic products is also possible upon sintering using the present technique.
- Company:Tohoku Techno Arch Co., Ltd.
- Price:Other