Title :
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
Abstract :
We report synthesis of BaTiO3-(Bi1/2Na1/2)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 ρRT 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 (Bi1/2Na1/2)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-(Bi0.5Na0.5)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;
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
DOI :
10.1109/ISAF.2012.6297799
