Structural effects of Li and K additives on the columbite precursor and 0.9PMN–0.1PT powders

Bruno, J. C.; Cavalheiro, Alberto Adriano; Zaghete, M. A.; Cilense, M.; Varela, José Arana

doi:10.1016/j.matchemphys.2003.11.014

Cited by 23 publications

(16 citation statements)

References 14 publications

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“…Furthermore, to prepare the PMN-PT compositions using the columbite route, it is necessary to insert a titanium-carrier component (TiO 2 , PT) during PMN-PT synthesis, which makes it harder to reproduce the final properties. However, a new method has been proposed to improve the PMN-PT preparation [7], based on the previous insertion of titanium into the columbite precursor. The main advantage of this method is the suppression of the titanium-carrier component, improving and simplifying the obtaining process.…”

Section: Introductionmentioning

confidence: 99%

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

et al. 2006

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This study aims to demonstrate how the chemical homogeneity of B cations affects the microstructure and electrical responses of (1-x)PMN-xPT ceramics. Two methodologies were employed to synthesize three different compositions, with x assuming the values 0.10, 0.28, and 0.35. If compared to conventional method, the Ti-modified columbite route, which is characterized by higher B cation homogeneity, leads to PMN-PT powders and ceramics with lower content of PNT pyrochlore phase and, for 0.65PMN-0.35PT composition, minor amount of tetragonal phase is found. Conclusively, PMN-PT ceramics obtained by modified route favors B cations homogeneity, enhancing the dielectric, ferroelectric and piezoelectric properties.

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Section: Introductionmentioning

confidence: 99%

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

et al. 2006

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“…The starting materials used to prepare the MN T precursors, as described earlier [6], are analytically pure: Nb 2 O 5 , (MgCO 3 ) 4 .Mg(OH) 2. 5H 2 O, Ti(OC 3 H 7 ) 4 , and Li 2 CO 3 .…”

Section: Methodsmentioning

confidence: 99%

“…Furthermore, to prepare PMN-PT compositions using the columbite route is necessary to provide a titanium component becoming hard to keep the reproducibility of all fabrication stages. This way, to skip out the increment of additional component, we proposed a previous Ti insertion into the MN orthorhombic structure, adopting the Timodified columbite precursor method [6]. This method consists in the synthesis of the MN T precursor, followed by the reaction with PbO to form the PMN-PT powder.…”

Section: Introductionmentioning

confidence: 99%

Study of Ti-Modified Columbite Route and the Effect of Lithium Doping in 0.9PMN-0.1PT Ceramics

et al. 2006

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The influence of lithium on the structural characteristics of PMN-PT ceramic was studied. The synthesis of PMN-PT powders using this precursor leads to the formation of high amount of perovskite phase. The insertion of Li + ions in B-site affects the microstructure because the rise in mass transport changes the mechanical characteristics of sintered ceramic. Higher values of K m and T m were gotten when lithium is inserted into perovskite phase. Secondary phase was found when lithium content increase beyond 1 mol%, besides the occurrence of transgranular fractures in sintered ceramic. Also, the additive acts increasing the relaxor behavior.

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“…In addition, the dielectric constants for four end members, NiTiNb 2 O 8 , CoTiNb 2 O 8 , NiTiTa 2 O 8 and CoTiTa 2 O 8 were between 25 and 75 at a temperature range of room temperature to 300°C. On the other hand, the solid solution systems M 2+ /Ti 4+ /M 5+ /O (M 2+ : Mg, Zn; M 5+ : Nb, Ta), where the transitionmetals were substituted with either magnesium or zinc atom, had been reported to have four types of crystal structures as follows: Mg 0.167 Nb 0.333 Ti 0.5 O 2 with a rutile-type structure [7], (Mg 0.857 Ti 0.143 ) (Nb 0.857 Ti 0.143 ) 2 O 6 , with a columbite-type structure [8], ZnTiNb 2 O 8 with the α-PbO 2 -type structure [9], (Zn 0.15 Nb 0.3 Ti 0.55 )O 2 with a rutile-type structure [10] and Zn/Ti/Ta/O system with a spinel-type structure [11,12]. The dielectric behaviors of ATiM 2 O 8 (A: Mg, Zn; M: Nb, Ta) were reported to be a candidate for a microwave capacitor and sol-gel process or a sintering additive for these compounds was attempted to improve their property [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Crystal structure, photocatalytic and dielectric property of ATiM₂O₈ (A: Mg, Zn; M: Nb, Ta)

Kumada

Nakanome

Yanagida

et al. 2018

Journal of Asian Ceramic Societies

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Four types of oxides, ATiM 2 O 8 (A: Mg, Zn; M: Nb, Ta) were prepared by high-temperature solid-state reaction. MgTiNb 2 O 8 , ZnTiNb 2 O 8 and ATiTa 2 O 8 had rutile-type, α-PbO 2-type and trirutile-type structures, respectively. The crystal structures of these compounds were refined based on the synchrotron X-ray powder diffraction data with the following R-factors: R wp = 4.34% and R p = 2.21% for MgTiNb 2 O 8 ; R wp = 2.19% and R p = 1.52% for ZnTiNb 2 O 8 ; R wp = 9.03% and R p = 6.31% for MgTiTa 2 O 8 ; and R wp = 5.70% and R p = 4.16% for ZnTiTa 2 O 8. Their lattice parameters were a = 4.69585(8) and c = 3.04260(6) Å for MgTiNb 2 O 8 ; a = 4.67138 (6), b = 5.65916(7) and c = 5.00745(6) Å for ZnTiNb 2 O 8 ; a = 4.6876(2) and c = 9.1385(3) Å for MgTiNb 2 O 8 ; and a = 4.6987(7) and c = 9.1296(1) Å for ZnTiTa 2 O 8. The optical band gap for these compounds ranged from 2.98 to 3.15 eV and every compound exhibited a small amount of photocatalytic activity for phenol decomposition under UV light irradiation. However, no photocatalytic activity was observed under visible light irradiation. The dielectric constants for these compounds were between 25 and 125 at a temperature range of room temperature to 400°C.

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Structural effects of Li and K additives on the columbite precursor and 0.9PMN–0.1PT powders

Cited by 23 publications

References 14 publications

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

Study of Ti-Modified Columbite Route and the Effect of Lithium Doping in 0.9PMN-0.1PT Ceramics

Crystal structure, photocatalytic and dielectric property of ATiM₂O₈ (A: Mg, Zn; M: Nb, Ta)

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Structural effects of Li and K additives on the columbite precursor and 0.9PMN–0.1PT powders

Cited by 23 publications

References 14 publications

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

(1-x)PMN-xPT Ceramics Prepared by Conventional and Modified Columbite Route: Effect on Electrical Properties

Study of Ti-Modified Columbite Route and the Effect of Lithium Doping in 0.9PMN-0.1PT Ceramics

Crystal structure, photocatalytic and dielectric property of ATiM2O8 (A: Mg, Zn; M: Nb, Ta)

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Crystal structure, photocatalytic and dielectric property of ATiM₂O₈ (A: Mg, Zn; M: Nb, Ta)