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Barium Strontium Titanate (barium + strontium_titanate)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

{111} Twin Formation and Abnormal Grain Growth in Barium Strontium Titanate

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2003
Byoung-Ki Lee
Two series of experiments were performed to study the experimental conditions for the formation of {111} twins and related microstructures in barium strontium titanate ((Ba, Sr)TiO3). In the first series, the phase equilibria in the BaTiO3,SrTiO3,TiO2 system were determined. XRD and WDS analysis, done in the BaTiO3 -rich region, of 45(Ba,Sr)TiO3,10TiO2 samples annealed at 1250°C for 200 h in air showed that (Ba,Sr)TiO3 was in equilibrium with Ba6Ti17O40 (B6T17) and Ba4Ti13O30 phases with strontium solubility (Sr/(Ba + Sr)) of ,0.02 and 0.20, respectively. In the second series the microstructures of samples consisting of a mixture of (Ba,Sr)TiO3 and 2.0 mol% TiO2, were observed after sintering at 1250°C for 100 h in air. {111} twins formed only in the samples with faceted B6T17 second phase particles, similar to the case of BaTiO3. In these samples, abnormal grain growth occurred in the presence of the {111} twins. In contrast, no {111} twins formed and no abnormal grain growth occurred in the samples containing second phase particles other than B6T17. With an increased substitution of strontium for barium, the aspect ratio of abnormal grains containing {111} twin lamellae was reduced. This result was attributed to a reduction in the relative stability of the {111} planes with the strontium substitution. [source]

Electric-Field-Tunable Low Loss Multiferroic Ferrimagnetic,Ferroelectric Heterostructures

ADVANCED MATERIALS, Issue 20 2009
Jaydip Das
A novel monolithic multilayered ferrimagnetic, ferroelectric multiferroic heterostructure shows a remarkably large tuning of the magnetic response with an electric field. The heteroepitaxial stack is comprised of a near single crystal yttrium iron garnet (YIG) layer, a ferroelectric barium strontium titanate (BSTO) layer with good electric field tunability, and embedded platinum (Pt) electrodes. [source]

{111} Twin Formation and Abnormal Grain Growth in Barium Strontium Titanate

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2003
Byoung-Ki Lee
Two series of experiments were performed to study the experimental conditions for the formation of {111} twins and related microstructures in barium strontium titanate ((Ba, Sr)TiO3). In the first series, the phase equilibria in the BaTiO3,SrTiO3,TiO2 system were determined. XRD and WDS analysis, done in the BaTiO3 -rich region, of 45(Ba,Sr)TiO3,10TiO2 samples annealed at 1250°C for 200 h in air showed that (Ba,Sr)TiO3 was in equilibrium with Ba6Ti17O40 (B6T17) and Ba4Ti13O30 phases with strontium solubility (Sr/(Ba + Sr)) of ,0.02 and 0.20, respectively. In the second series the microstructures of samples consisting of a mixture of (Ba,Sr)TiO3 and 2.0 mol% TiO2, were observed after sintering at 1250°C for 100 h in air. {111} twins formed only in the samples with faceted B6T17 second phase particles, similar to the case of BaTiO3. In these samples, abnormal grain growth occurred in the presence of the {111} twins. In contrast, no {111} twins formed and no abnormal grain growth occurred in the samples containing second phase particles other than B6T17. With an increased substitution of strontium for barium, the aspect ratio of abnormal grains containing {111} twin lamellae was reduced. This result was attributed to a reduction in the relative stability of the {111} planes with the strontium substitution. [source]

Determination of the Oxygen Deficiency in Vacuum-Hot-Pressed Ferroelectric Ceramics Using a Thermogravimetric Technique

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2000
Qi Tan
An attempt to measure the oxygen deficiency in vacuum-hot-pressed ferroelectric target materials was made, using a thermogravimetric method. The approach was intended to measure the relative mass increase of oxygen-deficient sheet samples, with respect to an oxidized reference that was annealed in air. A saturation of mass change was achieved, which indicated a saturated oxidation state and provided a basis for further calculation of the oxygen deficiency in the samples. Results were obtained for barium strontium titanate and lead lanthanum zirconate titanate compositions, which shows the feasibility of applying the thermogravimetric method to ferroelectric materials. [source]