Gaseous penetration of Gd into BaTiO₃ ceramics and their electric characteristics

The gaseous penetration of Gd element into BaTiO₃ ceramics was reported in this paper. The penetration conditions and effects on electric characteristics of BaTiO₃ ceramics were studied. The results showed that the electric characteristics of BaTiO₃ ceramics changed obviously through the gaseous penetration of Gd element. When the Gd element content 2%(wt), the penetration temperature 860°C and the penetration time 4h, the resistivity was changed from 4.0×10¹² Ω·m to 2.76×10¹³ Ω·m. The conductance increased with increase of frequency and temperature. The grain resistance of Gd-penetration BaTiO₃ ceramics exhibited NTCR effect, but the grain boundary resistance showed PTCR effect. The grain boundary resistance was too much larger than the grain resistance, so the PTCR effect originated from the grain boundary. The dielectric constant of Gd-penetration BaTiO₃ ceramics decreased visibly with increase of frequency. The dielectric constant exhibited PTC effect, and the Curie-temperature had gone up to 130.6°C.