Fabrication and PTC Properties of Lead-Free Element-Modified Barium Titanate Semiconducting Ceramics with Tc130Â°C

Author

Takeda, H. ; Harinaka, H. ; Hoshi, Y. ; Kinoshida, T. ; Nishida, T. ; Uchiyama, K. ; Shimada, T. ; Katsuyama, Y. ; Shiosaki, T.

Author_Institution

Nara Inst. of Sci. & Technol., Nara

fYear

2007

fDate

27-31 May 2007

Firstpage

805

Lastpage

807

Abstract

The fabrication processes in air of semiconducting bismuth-and sodium-modified barium titanate, Ba_1-x(Bi_1/2Na_1/2)xTiO₃ (BBNT100x) ceramics were investigated for a lead-free PTC (positive temperature coefficient of resistivity) thermistor material usable over 130degC. The two processes and their electric properties are described. The Nb-doped BBNT6 ceramics and BBNT6 ones sintered with the oxygen-containing a-Zr metal powders have a resistivity at room temperature rho_RT on the order of 10³-10⁶ Omegacm and showed PTC behaviors. The BBNT20 ceramics displayed their resistivity changes over 200degC.

Keywords

barium compounds; bismuth compounds; ceramics; doping; electrical resistivity; niobium; powder technology; semiconductor materials; sintering; sodium compounds; thermistors; zirconium; BBNT100x ceramics; BaBi_0.5Na_0.5TiO₃; lead-free PTC thermistor material; niobium-doped BBNT6 ceramics; oxygen-containing a-zirconium metal powders; positive temperature resistivity coefficient; semiconducting bismuth-modified barium titanate; semiconducting sodium-modified barium titanate; sintering; Barium; Bismuth; Ceramics; Conductivity; Environmentally friendly manufacturing techniques; Fabrication; Lead compounds; Semiconductivity; Temperature; Titanium compounds;

fLanguage

English

Publisher

ieee

Conference_Titel

Applications of Ferroelectrics, 2007. ISAF 2007. Sixteenth IEEE International Symposium on

Conference_Location

Nara

ISSN

1099-4734

Print_ISBN

978-1-4244-1334-8

Electronic_ISBN

1099-4734

Type

conf

DOI

10.1109/ISAF.2007.4393408

Filename

4393408