An Aqueous Synthesis of Barium Titanate

Flaschen, S. S.

doi:10.1021/ja01628a030

Cited by 113 publications

(54 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The nanohoneycomb-structured diamond films may find applications in functional devices such as sensors and electrodes. [10] In addition, they are candidates for twodimensional photonic bandgap structure materials [11] for use in the UV-vis wavelength region, owing to their high refractive index and wide bandgap energy (e.g., 5.45 eV).…”

Section: Methodsmentioning

confidence: 99%

“…Syntheses of nanocrystalline oxides often produce crystal structures that are not thermodynamically stable. Cubic BaTiO 3 , [10] tetragonal ZrO 2 , [11] monoclinic Y 2 O 3 , [12] and g-Al 2 O 3 [13,14] are some examples of stabilization of metastable forms in the finely divided form. It is important to establish whether the stabilization is caused by the lower surface Gibbs energy of the metastable form relative to stable variety, as suggested by the molecular dynamics simulations of Blonski and Garofalini [15] on a and g-Al 2 O 3 .…”

Section: ±1mentioning

confidence: 99%

See 1 more Smart Citation

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell

et al. 2000

View full text Add to dashboard Cite

Most materials in their nanocrystalline state exhibit unusual properties. The tremendous enhancement of mechanical, physical, and chemical properties caused by the fine admixture of order (inside the crystallites) and disorder (in the grain boundary regions) is being exploited in a number of frontier technologies. A concern in the use of nanocrystalline materials is their stability during high temperature exposure, either while processing or in service. There is no experimental data in the literature on the Gibbs energy of formation of any nanocrystalline material and no standard technique is available for measurement, especially at elevated temperatures. Quantitative information on the thermodynamic driving force for degradation to the microcystalline state and mechanistic understanding of the degradation processes would be useful in the design and processing of nanocrystalline materials for new applications. Reliable information on surface and interfacial properties of ceramic materials, which provide important guidelines for understanding nanocrystalline materials, are not available in the literature, even for model systems. Magnesium aluminate, which is used as an adsorbent for removing surfactants from aqueous solutions, as a support material for transition metal and lanthanide phosphors, and as a catalyst, was selected as a model compound in this study.Reported in this communication is a novel application of the solid state electrochemical technique for probing the thermodynamic state of nanocrystalline MgAl 2 O 4 at high temperatures. The method has been used recently for the measurement of the Gibbs energy of microcrystalline MgAl 2 O 4 .[1] Although the principle of this method for thermodynamic measurements was outlined in the classic papers of Kiukkola and Wagner, [2,3] the technique has not been applied to nanocrystalline materials. The reversible electromotive force (emf) of the cell was measured as a function of temperature in the range 900 to 1250 K. The cell is written such that the right-hand electrode is positive. Single crystal CaF 2 was used as the solid electrolyte and the cell was operated under dry oxygen. The reference electrode consisted of an intimate equimolar mixture of MgO and MgF 2 powders, compacted at a pressure of 250 MPa. Similarly, the working electrode was a compacted equimolar mixture of MgAl 2 O 4 , a-Al 2 O 3 , and MgF 2 . The particle size of the powders used to prepare the reference and working electrodes usually vary from 2 to 10 mm. In a recent study of the Gibbs energy of formation of MgAl 2 O 4 , [1] the average size of the aluminate particles used, as determined by scanning electron microscopy (SEM), was 3 mm. In the present study, the measurements were made using nanocrystalline MgAl 2 O 4 powders, keeping all other conditions the same.To obtain constant and reversible emf at any given temperature, it was necessary to remove moisture completely in the ceramic enclosure surrounding the cell. Formation of CaO on the surface of CaF 2 , by the reaction of water vapor wi...

show abstract

Section: Methodsmentioning

confidence: 99%

Section: ±1mentioning

confidence: 99%

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Sol-gel processes have also been used to produce BT nanopowders, but the amorphous or precursor phases that were produced necessitated heating at high temperature in order to form the crystalline BT phase. The alkoxide-hydroxide method, first suggested by Flashen, has been extensively investigated for the synthesis of the BT nanopowders because crystalline BT nanopowders are easily produced at temperatures lower than 100 • C [9]. However, most studies focused on the initial stage of the formation of crystalline BT nanopowders at low temperatures (≤100 • C).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of highly tetragonal BaTiO3 nanopowders by a two-step alkoxide–hydroxide route

Joung

Kim

Song

et al. 2011

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…Preparation of fine powders of BaTiO 3 by a solution technique has been first reported in 1955 by reaction of titanium alkoxides with water solution of Ba(OH) 2 [1]. The very first attempts in preparation of BaTiO 3 starting from metal alkoxides have been reported by Mazdiyasni in the late 1960s [2].…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence investigations of Eu3+ doped BaTiO3 nanopowders fabricated using heterometallic tetranuclear alkoxide complexes

Pązik

Hreniak

Stręk

et al. 2008

Journal of Alloys and Compounds

View full text Add to dashboard Cite

An Aqueous Synthesis of Barium Titanate

Cited by 113 publications

References 0 publications

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell

Synthesis of highly tetragonal BaTiO3 nanopowders by a two-step alkoxide–hydroxide route

Photoluminescence investigations of Eu3+ doped BaTiO3 nanopowders fabricated using heterometallic tetranuclear alkoxide complexes

Contact Info

Product

Resources

About

An Aqueous Synthesis of Barium Titanate

Cited by 113 publications

References 0 publications

Nanocrystalline MgAl 2 O 4 : Measurement of Thermodynamic Properties Using a Solid State Cell

Nanocrystalline MgAl 2 O 4 : Measurement of Thermodynamic Properties Using a Solid State Cell

Synthesis of highly tetragonal BaTiO3 nanopowders by a two-step alkoxide–hydroxide route

Photoluminescence investigations of Eu3+ doped BaTiO3 nanopowders fabricated using heterometallic tetranuclear alkoxide complexes

Contact Info

Product

Resources

About

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell

Nanocrystalline MgAl ₂ O ₄ : Measurement of Thermodynamic Properties Using a Solid State Cell