Enhanced piezoelectric properties of (Bi0.5Na0.5)1－xBax TiO3 lead-free ceramics by sol-gel method

In this paper, the KNN powders with Li+ substituted (K0.5Na0.5)+ were prepared by the sol-gel method in order to make powders pure, (Na0.50+xK0.50-2xLix) -NbO3 (x=0, 0.04, 0.06, 0.08) ceramics were prepared by pressureless sintering. The phase composition of powders was determined by XRD. The effects of the Li+ substitution on piezoelectric and ferroelectric properties of ceramics were systematically studied for determining optimal Li+ content. Li+ can significantly increase the piezoelectric constant of ceramic. When Li+ content was 0.04, piezoelectric properties of ceramics were the best, d33=115 pC/N, Pr=6.35 μC/cm2, Ec=14.24 kV/cm.

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Photoluminescence, Ferroelectric, Dielectric and Piezoelectric Properties of Sol-Gel-Derived Er-Doped KNN-LN Lead-Free Multifunctional Ceramics

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.90.19 ◽

2014 ◽

Vol 90 ◽

pp. 19-24 ◽

Cited By ~ 1

Author(s):

Xiao Wu ◽

Mei Lin ◽

Chi Man Lau ◽

Kin Wing Kwok

Keyword(s):

Near Infrared ◽

Piezoelectric Properties ◽

Sol Gel ◽

Solid State Reaction Method ◽

Host Lattice ◽

Lead Free ◽

Gel Method ◽

Sol Gel Method ◽

Er Doped ◽

Dielectric And Piezoelectric Properties

A sol-gel method has been utilized to prepare lead-free 2 mol% Er-doped K0.5Na0.5NbO3-xLiNbO3 (Er-KNN-xLN, x = 0, 0.08 and 0.10) ceramics. The X-ray diffraction results show that the ceramics have the perovskite structure and Er3+ ions have diffused into the host lattice. Compared to the solid-state reaction method, the sol-gel method is favor to reduce the sintering temperatures (~ 50 °C) of ceramics. Better compositional homogeneity, as well as finer and uniform grains is resulted from the sol-gel process, which have been confirmed by the scanning electron microscope images. The photoluminescence properties of ceramic bulks have been systemically studied. Under the excitation of 980 nm, the ceramics exhibit visible up-conversion green (510-570 nm) and red (640-685 nm) emissions. The emission colors of them are located in the yellowish green region. The down-conversion emissions in near-infrared (1450-1650 nm) and mid-infrared (2600-2870 nm) regions have been exhibited. The ferroelectric, dielectric and piezoelectric properties of ceramics have also been investigated. Because of the good electrical and excellent photoluminescence performances, our sol-gel-derived Er-doped KNN-LN ceramics should have great potential for multifunctional optoelectronic applications, such as optical-electro integrated materials and devices.

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Ferroelectric and piezoelectric properties of lead-free (K,Na,Li)(Nb,Ta,Sb)O3 ceramics fabricated by using a citric-acid-assisted modified sol-gel method

Journal of the Korean Physical Society ◽

10.3938/jkps.61.966 ◽

2012 ◽

Vol 61 (6) ◽

pp. 966-970 ◽

Cited By ~ 1

Author(s):

Ju Sung Kim ◽

Jong Pil Kim ◽

Chang Won Ahn ◽

Ill Won Kim ◽

Byung Moon Jin

Keyword(s):

Citric Acid ◽

Piezoelectric Properties ◽

Sol Gel ◽

Lead Free ◽

Gel Method ◽

Sol Gel Method ◽

Ferroelectric And Piezoelectric Properties

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Piezoelectric Properties Study of KNN-LS Lead-Free Ceramics Synthesized by Sol-Gel Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.538.15 ◽

2014 ◽

Vol 538 ◽

pp. 15-18 ◽

Cited By ~ 1

Author(s):

Xin Jin ◽

Xing Hua Fu ◽

Wen Hong Tao ◽

Yang Lu Hou

Keyword(s):

Piezoelectric Coefficient ◽

Piezoelectric Properties ◽

Sintering Temperature ◽

Perovskite Phase ◽

Sol Gel ◽

Second Phase ◽

Gel Method ◽

Sol Gel Method ◽

Fine Grained ◽

Lead Free Ceramics

Morphotropic phase boundary (MPB) composition, KNaNbO3-0.052LiSbO3(KNN-LS) was synthesized by sol-gel method at this experiment. Sb2O3 was used as economic Sb source and the final dried gel was calcined at 650°C for 2h to obtain white nanopowder. The sintering experiment was carried out at the temperature range of 980°C-1130°C, and perovskite phase structure could be observed apparently below 1080°C. When the temperature reached 1080°C and above, the second phase Na3LiNb6O17 appeared meanwhile the piezoelectric coefficient (d33) decreased quickly. Its proven that fine-grained particles and low sintering temperature could be obtained in sol-gel route.

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KNN-BF Lead-Free Piezoelectric Ceramics Synthesized by Sol-Gel Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.740.3 ◽

2015 ◽

Vol 740 ◽

pp. 3-6

Author(s):

Guo Yuan Cheng ◽

Xing Hua Fu ◽

Xin Jin ◽

Wen Hong Tao ◽

Yu Qin Qiang

Keyword(s):

Comparative Analysis ◽

Citric Acid ◽

Dielectric Loss ◽

Sintering Temperature ◽

Sol Gel ◽

Piezoelectric Ceramics ◽

Lead Free ◽

Gel Method ◽

Sol Gel Method ◽

Metal Chelator

KNN-BF piezoelectric ceramics synthesized by sol-gel method in this experiment. By controlling bismuth and iron content in the system to study effects of them. We selected citric acid as metal chelator and ethylene glycol as esterification agent. PH maintained 5-6 during preparation of the sol. Sintering temperature of ceramic selected 1100°C. Preparation ceramics under these conditions and comparative analysis, the structure of ceramics is single perovskite and shap of crystals are square block. With the increase of x, properties of ceramics firstly increases and then decreases: d33, εr, Qm, Kpreaching the maximum, values of them were 136pC/N, 630(f =1KHz), 212, 0.41 respectively; dielectric loss to minimum is 0.07(f =1KHz); at this point, ceramics had best performance.

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