Semiconducting behavior of CaO-added BaTiO3-(Bi1/2Na1/2)TiO3 solid solution ceramics

Author

Takeda, Hiroaki ; Akutsu, Hitomi ; Zubair, Mohammad A. ; Hoshina, Takuya ; Tsurumi, Takaaki

Author_Institution

Grad. Sch. of Sci. & Eng., Tokyo Inst. of Technol., Tokyo, Japan

fYear

2012

fDate

9-13 July 2012

Firstpage

1

Lastpage

2

Abstract

We report synthesis of BaTiO₃-(Bi_1/2Na_1/2)TiO₃ (BT-BNT) semiconducting ceramics by conventional solid-state reaction method in air atmosphere. By adding CaO into the calcined BT-BNT powder, the resulting ceramics acquires the semiconductivity with the resistivity at room temperature ρ_RT value of 10²-10³ Ωcm and PTC behavior. The structure analysis using X-ray diffraction method, it was found that the CaO added BT-BNT ceramics consisted of perovskite-type ABO₃ single phase. Chemical composition analysis by inductively coupled plasma spectrometry disclosed a distinct evaporation of Na and Bi during sintering process. The quantity of evaporation of Na was higher than that of Bi. Based on these results, it was suggested that dominant substitution of Ca²⁺ for Na⁺ in the A site occurred, and then that part of Bi³⁺ separated from divalent (Bi_1/2Na_1/2)²⁺ pairs worked as a donor.

Keywords

X-ray chemical analysis; X-ray diffraction; barium compounds; bismuth compounds; calcination; calcium compounds; ceramics; electrical resistivity; evaporation; plasma materials processing; powder technology; powders; semiconductor growth; semiconductor materials; sintering; sodium compounds; solid solutions; CaO-BaTiO₃-(Bi_0.5Na_0.5)TiO₃; X-ray diffraction; air atmosphere; calcination; chemical composition analysis; energy dispersive X-ray spectra; evaporation; inductively-coupled plasma spectrometry; perovskite-type single phase; powder; resistivity; semiconducting behavior; sintering; solid solution ceramics; solid-state reaction method; structure analysis; temperature 293 K to 298 K; Atmosphere; Bismuth; Ceramics; Chemicals; Conductivity; Plasma temperature; Powders; PTC; defect chemistry; lead-free; rare-earth-free;

fLanguage

English

Publisher

ieee

Conference_Titel

Applications of Ferroelectrics held jointly with 2012 European Conference on the Applications of Polar Dielectrics and 2012 International Symp Piezoresponse Force Microscopy and Nanoscale Phenomena in Polar Materials (ISAF/ECAPD/PFM), 2012 Intl Symp

Conference_Location

Aveiro

Print_ISBN

978-1-4673-2668-1

Type

conf

DOI

10.1109/ISAF.2012.6297799

Filename

6297799