Journal ArticleDOI
The positive temperature coefficient of resistivity in barium titanate
TLDR
In this article, the influence of the processing parameters on the PTCR related properties is discussed, and special emphasis is placed on the phenomenon that the conductivity and grain size decrease with increasing donor concentration above ∼ 0.3 at%.Abstract:
Positive temperature coefficient of resistivity (PTCR) materials have become very important components, and among these materials barium titanate compounds make up the most important group. When properly processed these compounds show a high PTCR at the Curie temperature (the transition temperature from the ferroelectric tetragonal phase to the paraelectric cube phase). In the first half of this paper literature related to the resistivity-temperature behaviour is discussed. As explained by the well established Heywang model, the PTCR effect is caused by trapped electrons at the grain boundaries. From reviewing experimental results in the literature it is clear that the PTCR effect can not be explained by assuming only one kind of electron trap. It is concluded that as well as barium vacancies, adsorbed oxygen as 3d-elements can act as electron traps. In the second half of this paper, the influence of the processing parameters on the PTCR related properties is discussed. Special emphasis is placed on the phenomenon that the conductivity and grain size decrease abruptly with increasing donor concentration above ∼ 0.3 at%. Several models explaining this phenomenon are discussed and apparent discrepancies in experimental data are explained.read more
Citations
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Journal ArticleDOI
Impedance studies of Sr modified BaZr0.05Ti0.95O3 ceramics
Shrabanee Sen,R. N. P. Choudhary +1 more
TL;DR: In this paper, the electrical properties of polycrystalline samples of (Ba1−xSrx)(Zr0.05Ti0.95)O3 (x=0, 0.03,0.06 and 0.09) (BSZT) were prepared by a high-temperature solid-state reaction technique.
Journal ArticleDOI
A comparative study on the electrical conduction mechanisms of (ba0.5sr0.5)tio3 thin films on pt and iro2 electrodes
Cheol Seong Hwang,Byoung Taek Lee,Chang Seok Kang,Jin-Won Kim,Ki Hoon Lee,Hag-Ju Cho,Hideki Horii,Wan Don Kim,Sang-In Lee,Young Bum Roh,Moonyong Lee +10 more
TL;DR: In this article, the authors studied the Schottky emission behavior of Pt/(Ba 0.5Sr0.5)TiO3 (BST)/Pt, IrO2/BST/IrO2, and Pt/Bst/Pt capacitors with potential barrier heights of about 1.5-1.6 eV.
Journal ArticleDOI
Solid Solubility of Holmium, Yttrium, and Dysprosium in BaTiO3
TL;DR: In this article, the solid solubility of R ions (R = Ho3+, Dy3+, and Y3+) in the BaTiO3 perovskite structure was studied by quantitative electron-probe microanalysis (EPMA) using wavelength-dispersive spectroscopy (WDS), scanning electron microscopy (SEM), and X-ray diffractometry (XRD).
Journal ArticleDOI
Defect chemistry and electrical properties of sodium bismuth titanate perovskite
TL;DR: In this article, the authors review how to tune the electrical properties of NBT via several mechanisms, including A-site Na or Bi non-stoichiometry, isovalent substitution, and acceptor-and donor-doping.
Journal ArticleDOI
Donor-doping and reduced leakage current in Nb-doped Na0.5Bi0.5TiO3
TL;DR: In this article, the authors show low levels of Nb-doping (≤1 at. %) on the Ti-site in the well-known lead-free piezoelectric perovskite oxide Na 0.5Bi0.5TiO3 (NBT) produces completely different behaviors whereby much higher resistivity is obtained.
References
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Journal ArticleDOI
Impedance and modulus spectroscopy of semiconducting BaTiO3 showing positive temperature coefficient of resistance
TL;DR: In this article, an analysis of ac impedance data using the complex impedance plane representation gives the dc resistance of polycrystalline barium titanate (PTCR) ceramics.
Journal ArticleDOI
Resistivity Anomaly in Doped Barium Titanate
TL;DR: In this article, the authors reexamined the barrier-layer model to explain the anomalous increase in resistivity that occurs in doped BaTiO3 in the light of data obtained from more recent experiments.
Journal ArticleDOI
Some aspects of semiconducting barium titanate
TL;DR: In this article, the ferroelectric Curie point theory was extended with a ferro-electric effect to the case of semiconducting BaTiO 3 and showed an enormous increase in resistivity above the Curie points.