Abstract
Phase-pure perovskite lead titanate with various morphologies has been synthesized by a hydrothermal method at 150 °C. Particle shapes include cubic, tabular, and aggregated platelike shapes. The feedstock concentration greatly influences particle morphology of the hydrothermally derived PbTiO3. At a concentration of 0.05 M, the tabular particles form while cubic particles are produced at 0.1 M. Aggregated plateletlike particles are synthesized at 0.125 M. It was observed that both tabular and cubic particles directly precipitate from the coprecipitated precursor gel. In contrast, the plateletlike shaped intermediate phase appears during the initial stage of reaction at 0.125 M and in situ transforms into perovskite PbTiO3 during further hydrothermal treatment. The intermediate phase preserves its particle shape during transformation and, acting as a template, gives rise to the final tabular PbTiO3 particles. It is demonstrated that only base reagents such KOH and NaOH, which provide a highly basic condition (i.e., pH > 14), promote transformation of the coprecipitated gel into the perovskite PbTiO3. A Hancock and Sharp kinetic analysis in conjunction with microstructural evidence suggests that the formation mechanism is dissolution and recrystallization in which the degree of supersaturation plays an important role in dictating the crystallographic particle phase and morphology of the particles. An experimentally constructed solubility diagram indicates that an excess lead condition is necessary to compensate for loss of lead species and to increase supersaturation to expedite precipitation of PbTiO3 at highly alkaline conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 866-875 |
| Number of pages | 10 |
| Journal | Journal of Materials Research |
| Volume | 14 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1999 Jan 1 |
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
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Particle-shape control and formation mechanisms of hydrothermally derived lead titanate. / Moon, Joo Ho; Carasso, Melanie L.; Krarup, Henrik G.; Kerchner, Jeffrey A.; Adair, James H.
In: Journal of Materials Research, Vol. 14, No. 3, 01.01.1999, p. 866-875.Research output: Contribution to journal › Article
TY - JOUR
T1 - Particle-shape control and formation mechanisms of hydrothermally derived lead titanate
AU - Moon, Joo Ho
AU - Carasso, Melanie L.
AU - Krarup, Henrik G.
AU - Kerchner, Jeffrey A.
AU - Adair, James H.
PY - 1999/1/1
Y1 - 1999/1/1
N2 - Phase-pure perovskite lead titanate with various morphologies has been synthesized by a hydrothermal method at 150 °C. Particle shapes include cubic, tabular, and aggregated platelike shapes. The feedstock concentration greatly influences particle morphology of the hydrothermally derived PbTiO3. At a concentration of 0.05 M, the tabular particles form while cubic particles are produced at 0.1 M. Aggregated plateletlike particles are synthesized at 0.125 M. It was observed that both tabular and cubic particles directly precipitate from the coprecipitated precursor gel. In contrast, the plateletlike shaped intermediate phase appears during the initial stage of reaction at 0.125 M and in situ transforms into perovskite PbTiO3 during further hydrothermal treatment. The intermediate phase preserves its particle shape during transformation and, acting as a template, gives rise to the final tabular PbTiO3 particles. It is demonstrated that only base reagents such KOH and NaOH, which provide a highly basic condition (i.e., pH > 14), promote transformation of the coprecipitated gel into the perovskite PbTiO3. A Hancock and Sharp kinetic analysis in conjunction with microstructural evidence suggests that the formation mechanism is dissolution and recrystallization in which the degree of supersaturation plays an important role in dictating the crystallographic particle phase and morphology of the particles. An experimentally constructed solubility diagram indicates that an excess lead condition is necessary to compensate for loss of lead species and to increase supersaturation to expedite precipitation of PbTiO3 at highly alkaline conditions.
AB - Phase-pure perovskite lead titanate with various morphologies has been synthesized by a hydrothermal method at 150 °C. Particle shapes include cubic, tabular, and aggregated platelike shapes. The feedstock concentration greatly influences particle morphology of the hydrothermally derived PbTiO3. At a concentration of 0.05 M, the tabular particles form while cubic particles are produced at 0.1 M. Aggregated plateletlike particles are synthesized at 0.125 M. It was observed that both tabular and cubic particles directly precipitate from the coprecipitated precursor gel. In contrast, the plateletlike shaped intermediate phase appears during the initial stage of reaction at 0.125 M and in situ transforms into perovskite PbTiO3 during further hydrothermal treatment. The intermediate phase preserves its particle shape during transformation and, acting as a template, gives rise to the final tabular PbTiO3 particles. It is demonstrated that only base reagents such KOH and NaOH, which provide a highly basic condition (i.e., pH > 14), promote transformation of the coprecipitated gel into the perovskite PbTiO3. A Hancock and Sharp kinetic analysis in conjunction with microstructural evidence suggests that the formation mechanism is dissolution and recrystallization in which the degree of supersaturation plays an important role in dictating the crystallographic particle phase and morphology of the particles. An experimentally constructed solubility diagram indicates that an excess lead condition is necessary to compensate for loss of lead species and to increase supersaturation to expedite precipitation of PbTiO3 at highly alkaline conditions.
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U2 - 10.1557/JMR.1999.0116
DO - 10.1557/JMR.1999.0116
M3 - Article
VL - 14
SP - 866
EP - 875
JO - Journal of Materials Research
JF - Journal of Materials Research
SN - 0884-2914
IS - 3
ER -