Preparation of submicrometer ferroelectric particles by wet-chemical methods

Schlag, Stefan; Eicke, Hans‐Friedrich; Mathys, Daniel; Guggenheim, R.

doi:10.1021/la00021a073

Cited by 24 publications

(11 citation statements)

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“…Size-effect-phenomena issues in ferroelectrics have been of interest for many years; however, recent advances in chemical synthesis and thin-film deposition have caused this problem to gain new momentum. [11][12][13][14][15][16][17][18][19][20][21][22][23][24] However, despite the large number of recent investigations regarding the effect of size on the ferroelectric transition, there has been a substantial disagreement in the critical sizes that have been reported. The inconsistent elastic and electric boundary conditions established from one process to another may account for some of the variations.…”

Section: Introductionmentioning

confidence: 99%

Intrinsic Size Effects in a Barium Titanate Glass‐Ceramic

McCauley

Newnham

Randall

1998

Journal of the American Ceramic Society

224

104

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A series of glass ceramics have been synthesized to produce bulk materials with nanometer-sized barium titanate (BaTiO 3 ) crystals grown in a residue glass matrix. Structureproperty relations have been made to determine the size distribution and the dielectric temperature dependence of the ceramics. Through dielectric and density mixing laws, it has been inferred that depolarization fields limit the dielectric polarizability of the particles and influence the transition temperature. The transition temperature, dielectric anomaly broadening, and peak dielectric constant all scale systematically with the mean size of the BaTiO 3 crystals, which is consistent with an intrinsic size effect. In addition, scaling the transition temperature with the Ishikawa relation predicts a critical size of 17 nm, for which BaTiO 3 cannot support a ferroelectric transition. These results are discussed in relation to other size studies on ferroelectric materials.

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Section: Introductionmentioning

confidence: 99%

Intrinsic Size Effects in a Barium Titanate Glass‐Ceramic

McCauley

Newnham

Randall

1998

Journal of the American Ceramic Society

224

104

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“…15 -16 However, when applied to a binary system such as BaTi0 3 , problems with the control of the stoichiometry have been reported. 17 The methodology used here for the preparation of nonagglomerated nanospherical precursor particles with a zircon composition, a binary oxide, may extend microemulsion-based methods for the preparation of nanospherical particles of other multicomponent ceramic powders and precursors. This paper reports the preparation of nanospherical amorphous precursor particles with a stoichiometric zircon composition, by hydrolysis of mixtures of tetraethylorthosilicate and zirconium n-propoxide within the water droplets of water-in-oil ~icroemulsions.…”

Section: Introductionmentioning

confidence: 99%

“…15,16 However, when applied to a binary system such as BaTiO 3 , problems with the control of the stoichiometry have been reported. 17 The methodology used here for the preparation of non-agglomerated nanospherical precursor particles with a zircon composition, a binary oxide, may extend microemulsion-based methods for the preparation of nanospherical particles of other multicomponent ceramic powders and precursors.…”

Section: Introductionmentioning

confidence: 99%

Preparation of nanospherical amorphous zircon powders by a microemulsion-mediated process

Tartaj

Jonghe

2000

J. Mater. Chem.

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A modified reverse micelle process has been developed for the synthesis of nanospherical amorphous zircon precursor powders. It has been found that the hydrolysis of a mixture of zirconium and silicon alkoxides within the water phase of a microemulsion can produce amorphous, nanospherical particles with a stoichiometric ZrSi0 4 composition.Microemulsions were obtained by using cyclohexane as the oil phase, ammonium solutions as the aqueous phase, and lgepal Co520 as surfactant. A precise control of the stoichiometry of the powders was achieved after the starting silicon and zirconium alkoxides were appropriately modified. In particular, silicon alkoxide was pre-hydrolyzed under acidic conditions while the zirconium alkoxide was reacted with chelating agents.The as-prepared powders consisted of amorphous nanospherical particles with compositional homogeneity. Heating of powders led first to incipient tetragonal zirconia crystallization at a temperature of 900°C. The onset of crystalline zircon formation was

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“…It is, however, possible to recycle them when the microemulsion processing technique is fully developed and matured for industrial applications. Schlag and co-workers 27 have recently tried without success to synthesize fine barium titanate particles of high purity from an inverse microemulsion consisting of decane (oil phase), a nonionic surfactant (Genapol OX30, Hoechst, Switzerland), and an aqueous phase containing barium and titanium chlorides. Oxalate precipitates were formed in the nanosized microemulsion domains; however, they were unable to obtain a single-phase BaTiO 3 when the precursor was calcined at various temperatures ranging from 400°to 1200°C.…”

Section: Introductionmentioning

confidence: 99%

Ultrafine Barium Titanate Powders via Microemulsion Processing Routes

Wang

Fang

et al. 1999

Journal of the American Ceramic Society

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Three processing routes have been used to prepare barium titanate powders, namely conventional coprecipitation, single-microemulsion coprecipitation using diether oxalate as the precipitant, and double-microemulsion coprecipitation using oxalic acid as the precipitant. A single-phase perovskite barium titanate was obtained when the doublemicroemulsion-derived oxalate precursor was calcined for 2 h at a temperature of as low as 550°C, compared to 600°C required by the single-microemulsion-derived precursor. A calcination for 2 h at >700°C was required for the conventionally coprecipitated precursor in order to develop a predominant barium titanate phase. It was, however, impossible to eliminate the residual TiO 2 impurity phase by raising the calcination temperature, up to 1000°C. The microemulsion-derived barium titanate powders also demonstrated much better powder characteristics, such as more refined crystallite and particle sizes and a much lower degree of particle agglomeration, than those of the conventionally coprecipitated powder, although they contained ∼0.2 wt% BaCO 3 as the impurity phase.

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Preparation of submicrometer ferroelectric particles by wet-chemical methods

Cited by 24 publications

References 0 publications

Intrinsic Size Effects in a Barium Titanate Glass‐Ceramic

Intrinsic Size Effects in a Barium Titanate Glass‐Ceramic

Preparation of nanospherical amorphous zircon powders by a microemulsion-mediated process

Ultrafine Barium Titanate Powders via Microemulsion Processing Routes

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