Electric Field-Induced Birefringence in Single Grain Boundaries of PTCR Barium Titanate Ceramics above the Curie Point

2003 ◽  
Vol 290 (1) ◽  
pp. 71-81
Author(s):  
Makoto Kuwabara ◽  
Kouichi Hamamoto
Keyword(s):  
Barium Titanate ◽  
Electric Field ◽  
Grain Boundaries ◽  
Curie Point ◽  
Single Grain ◽  
Titanate Ceramics

Shift of the Curie Point of Barium Titanate Ceramics with Sintering Temperature

2005 ◽  
Vol 80 (10) ◽  
pp. 2590-2596 ◽  
Author(s):  
Makoto Kuwabara ◽  
Hirofumi Matsuda ◽  
Natsuko Kurata ◽  
Eiji Matsuyama
Keyword(s):  
Barium Titanate ◽  
Curie Point ◽  
Sintering Temperature ◽  
Titanate Ceramics

scholarly journals Temperature-stable Barium Titanate Ceramics Containing Niobium Pentoxide

1976 ◽  
Vol 2 (4) ◽  
pp. 241-247 ◽  
Author(s):  
Ian Burn
Keyword(s):  
Barium Titanate ◽  
Solid Solutions ◽  
Curie Point ◽  
Niobium Pentoxide ◽  
High Permittivity ◽  
Temperature Range ◽  
Titanate Ceramics ◽  
Large Cation

Niobium is known to lower the Curie point and broaden the permittivity peak of barium titanate. However, the distribution of niobium in sintered barium titanate is often not homogeneous, being influenced by such preparation variables as large cation/small cation stoichiometry and firing conditions. In addition to these factors, it was found that, at least up to about 5 mol% Nb, the distribution of niobium in the barium titanate grains could be regulated by small amounts (<1 mol%) of oxides of Co, Mg, Ni or Mn. These oxides appear to form niobates that produce high permittivity solid solutions in the “skins” of the barium titanate grains and permit dielectrics to be obtained with permittivity (K≃¯2000), stable to within ±10% over the temperature range −55℃ to 125℃.

Characteristics of Porous Sb-Doped Barium Titanate Ceramics Fabricated by Adding Graphite

2015 ◽  
Vol 1107 ◽  
pp. 9-13
Author(s):  
Nurafizalwani Ayub ◽  
Ramli Omar ◽  
Mohamad Deraman ◽  
Ibrahim Abutalib ◽  
Zalita Zainuddin ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Resistivity ◽  
Barium Titanate ◽  
Grain Boundaries ◽  
Barrier Height ◽  
Perovskite Structure ◽  
Density Structure ◽  
Exothermic Reactions ◽  
Doped Barium Titanate ◽  
Titanate Ceramics

Porous Sb-doped barium titanate (Sb-BaTiO3) ceramics were fabricated by adding various amounts of graphite powders. The density, structure, microstructure, porosity and electrical resistivity of the porous Sb-BaTiO3 ceramics produced without and with graphite were investigated. All the sintered ceramics showed a tetragonal perovskite structure, irrespective of the amount of graphite added. The porosity of the ceramics increased and the grain size decreased with increasing graphite addition which mainly due to the exothermic reactions of the graphite and oxygen molecules in the ceramics. The prepared porous Sb-BaTiO3 ceramics exhibit PTCR behavior where the PTCR jump of the ceramics with graphite was about 103 which is higher than that of the ceramics without graphite. The increasing in the PTCR jump with increasing graphite addition was attributed mainly due to the increase in the electrical barrier height of grain boundaries and the porosity. It was found that the graphite is an effective pore forming agent for fabricating porous BaTiO3-based ceramics.

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