The Electronic Properties of the $BT-(BaNaK)(TiNb)O_3$ System for Lead Free PTC

We weal know that PbO was poisonous and prone to volatilize, then to pollute the circumstance and hurt to people, so we should dope other innocuous additives instead of lead to increase Tc of composite PTC material. In order to prepare lead-free $BaTiO_3$-based PTC with middle Curie point, the incorporation on $(BaNaK)(TiNb)O_3$ into $BaTiO_3$-based ceramics was investigated on samples containing 0.05, 0.07 and 0.1mol% of $(BaNaK)(TiNb)O_3$. $(BaNaK)(TiNb)O_3$ was compounded as standby material by conventional solid-state reaction technique. The starting materials were $Na_2O_3$,$K_2CO_3$, $BaCO_3$, $TiO_2$ and $Nb_2O_5$ powder, and using solid-state reaction method, too. The microstructure of samples were investigated by SEM, DSC, XRD and dielectric properties. Phase composition and lattice parameters were investigated by X-ray diffraction. Also, we are measure the resistivity of sintered bodies with calcinations condition.