Phase transitions and electrical characteristics of tungsten substituted barium titanate

ABSTRACTBarium titanate ceramics have been obtained by sol-gel methods. The dielectric investigations of these materials revealed the existence of diffuse ferroelectric transitions. By using a phenomenological model, we could demonstrate the existence of a simple relationship between the diffuse character of the transition and the sample grain-size. This effect has been attributed to interactions between charged defects on the grain surfaces and the spontaneous polarization of the material.

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Electrical characteristics and lifetimes of microdischarge devices having thin dielectric films of aluminum oxide,boron nitride, or barium titanate

Electronics Letters ◽

10.1049/el:20030430 ◽

2003 ◽

Vol 39 (10) ◽

pp. 773 ◽

Cited By ~ 12

Author(s):

S.-J. Park ◽

J.G. Eden

Keyword(s):

Barium Titanate ◽

Boron Nitride ◽

Aluminum Oxide ◽

Dielectric Films ◽

Electrical Characteristics ◽

Thin Dielectric Films

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Effect of Grain Size on Phase Transitions and Dielectric Properties of Nano-Crystalline Barium Titanate Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.602-604.192 ◽

2012 ◽

Vol 602-604 ◽

pp. 192-196

Author(s):

Li Ming Wang ◽

Xiang Yun Deng ◽

Hai Tao Zhang ◽

Jian Bao Li ◽

Di Chen ◽

...

Keyword(s):

Phase Transition ◽

Grain Size ◽

Phase Transitions ◽

Barium Titanate ◽

Fine Grain ◽

Nano Crystalline ◽

Plasma Sintering ◽

Transmission Electron ◽

Spark Plasma ◽

Titanate Ceramics

Barium titanate (BaTiO3) ceramics with grain size varied from 1000 to 8 nm were prepared by two step sintering method (TSS) and spark plasma sintering (SPS), respectively. Mixture structures of BaTiO3 ceramics were proved by in-situ temperature high resolution x-ray diffraction. Multiple ferroelectric domains present in nano-crystalline BaTiO3 ceramics were observed by transmission electron microscope. The evolution of phase transitions supported the existence of intrinsic mechanism. Dielectric loss of fine grain size BaTiO3 was higher than coarse grain size during Curie phase transition due to diffuse phase transition and grain boundary effects.

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Ferroelectric phase transitions in substituted barium titanate and lead zirconate titanate

Ferroelectrics ◽

10.1080/00150198408215852 ◽

1984 ◽

Vol 54 (1) ◽

pp. 207-210 ◽

Cited By ~ 6

Author(s):

Wolfram Wersing

Keyword(s):

Phase Transitions ◽

Barium Titanate ◽

Lead Zirconate Titanate ◽

Ferroelectric Phase ◽

Lead Zirconate ◽

Zirconate Titanate ◽

Ferroelectric Phase Transitions

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Dielectric investigations of La-doped barium titanate

Processing and Application of Ceramics ◽

10.2298/pac1003193r ◽

2010 ◽

Vol 4 (3) ◽

pp. 193-198 ◽

Cited By ~ 11

Author(s):

Tadas Ramoska ◽

Juras Banys ◽

Ricardas Sobiestianskas ◽

Mirjana Vijatovic-Petrovic ◽

Jelena Bobic ◽

...

Keyword(s):

Phase Transitions ◽

Barium Titanate ◽

High Frequency ◽

Low Frequency ◽

High Temperature Phase ◽

Temperature Phase ◽

Relaxational Process ◽

Pechini Process ◽

La Doped ◽

Curie Temperature Tc

In the present paper results of the dielectric investigation of barium titanate (BaTiO3) doped with different concentrations of lanthanum are presented. Ceramic samples were prepared by the Pechini process. With increased doping the grain size of ceramics decreases from 2.5 ?m in pure samples down to 0.2 ?m in 0.5 mol% La - doped BaTiO3. Ceramics showed maximally enhanced dielectric permittivity around low-, room and high temperature phase transitions, which are the phase transitions of the pure BaTiO3. The Curie temperature, TC, is lowered by 30 K with increase of doping concentration to 0.5 mol% La. Dielectric spectra revealed three parts: low frequency part which is caused by conductivity process, middle frequency relaxational process part and high frequency relaxational/polar modes contribution.

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