PHASE TRANSITION, DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF NaNbO3–Ba0.85Ca0.15(Ti0.9Zr0.1)O3 LEAD-FREE CERAMICS

2012 ◽  
Vol 05 (03) ◽  
pp. 1250033 ◽  
Author(s):  
YUQING LEI ◽  
HONG WU ◽  
DUNMIN LIN ◽  
QIAOJI ZHENG ◽  
XIAOCHUN WU ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
High Concentration ◽  
Lead Free Ceramics ◽  
Sintering Method ◽  
Dielectric And Piezoelectric Properties

A new lead-free solid solution of (1–x) NaNbO 3-x Ba 0.85 Ca 0.15( Ti 0.9 Zr 0.1) O 3 was prepared by a traditional sintering method and its phase transition, dielectric and piezoelectric properties were studied. Ba 0.85 Ca 0.15( Ti 0.9 Zr 0.1) O 3 diffuses into NaNbO3 lattices to form a new solid solution with perovskite structure. The addition of Ba 0.85 Ca 0.15( Ti 0.9 Zr 0.1) O 3(x≥0.025) transforms NaNbO3 from antiferroelectric to ferroelectric. The diffusive ferroelectric–paraelectric phase transition is induced in the ceramics with high concentration of Ba 0.85 Ca 0.15( Ti 0.9 Zr 0.1) O 3. The ceramics with x = 0.05–0.125 possess large Pr values of 18.6–25.5 μC/cm2. A morphotropic phase boundary between tetragonal and orthorhombic phases is formed at 0.05 < x < 0.15, leading to a significant enhancement of piezoelectric properties. The ceramic with x = 0.125 situated near the morphotropic phase boundary exhibits the optimum piezoelectric properties: d33 = 151 pC/N and kp = 31.6%.

Two-Step Sintering, Microstructure and Electrical Properties of (Ba, Ca)(Ti, Zr)O3 Lead-Free Ceramics

2015 ◽  
Vol 749 ◽  
pp. 79-83
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Electrical Properties ◽  
Piezoelectric Properties ◽  
Orthorhombic Phase ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Average Grain Size ◽  
Sintering Method ◽  
Dielectric And Piezoelectric Properties

In this work, the (Ba1-xCax)(Ti1-yZry)O3 lead-free ceramics were prepared by the two-step sintering method, and effects of Ca and Zr contents on phase structure, densification, microstructure, and electrical properties were investigated. It was found that all samples showed orthorhombic phase. The highest density of 5.84 ± 0.01 g/cm3 was achieved in x = 0.05, y = 0.05 sample. The average grain size, phase transition temperature, dielectric and piezoelectric properties significantly decreased by introducing of the Ca/Zr content. The ceramics with a small amount of Ca and Zr maintain good piezoelectric properties, and a lower dielectric loss. The composition with x = 0.05, y = 0.025 demonstrated optimum electrical properties of d33 ∼211 pC/N, TC ∼ 119 °C, εr ∼ 1788, and tanδ ∼ 0.04.

Na/K RATIOS DEPENDENCE OF PIEZOELECTRIC AND FERROELECTRIC PROPERTIES IN (K1-xNax)NbO3 LEAD-FREE CERAMICS

2011 ◽  
Vol 01 (04) ◽  
pp. 471-478 ◽  
Author(s):  
HONGLIANG DU ◽  
SHAOBO QU ◽  
ZHUO XU ◽  
XIAOYONG WEI ◽  
WANCHENG ZHOU ◽  
...  
Keyword(s):  
Solid State ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Obvious Effect ◽  
Lead Free Ceramics ◽  
Solid State Sintering

In order to clarify the Na/K ratios dependence of piezoelectric properties, ( K 1-x Na x) NbO 3 ceramics were prepared by conventional solid-state sintering at x = 0.4–0.6 with a smaller compositional interval (0.02 mol). The results demonstrate that the Na/K ratios have obvious effect on piezoelectric and ferroelectric properties of ( K 1-x Na x) NbO 3 ceramics. Piezoelectric and ferroelectric properties show the maximum (d33 = 147 pC/N, kp = 0.40, and Pr = 24 μC/cm2) at x = 0.54, which is not consistent with conventional viewpoint. The reasons should be attributed to the existence of a phase boundary at x = 0.54 mol, which is similar to the morphotropic phase boundary in Pb(Zr,Ti)O3 ceramics.

Piezoelectric properties of lead-free (Na0.5Bi0.5)TiO3–(Na0.5K0.5)NbO3–BaTiO3 ceramics

2008 ◽  
Vol 23 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Seung-Ho Lee ◽  
Chang-Bun Yoon ◽  
Sung-Mi Lee ◽  
Hyoun-Ee Kim ◽  
Kyung-Woo Lee
Keyword(s):  
Crystal Structure ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Microstructural Evolution ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Cubic Phase ◽  
Lead Free Ceramics ◽  
Wide Range

The microstructural evolution and piezoelectric properties of lead-free ceramics (0.98-x)(Na0.5Bi0.5)TiO3–x(Na0.5K0.5)NbO3–0.02BaTiO3 (0 ⩽ x ⩽ 0.98, abbreviated as (0.98-x)NBT–xNKN–0.02BT) were investigated. The effects of the amount of NKN on the crystal structure, microstructural evolution, and piezoelectric properties were examined. The 0.93NBT–0.05NKN–0.02BT ceramics having a lower NKN content gave good performances with piezoelectric properties of d33 = 140 pC/N and kp = 21%, because of the soft additive Nb5+ ions at the B sites. However, a paraelectric cubic phase was observed in the wide range of compositions between x = 0.1 and x = 0.9. At a higher NKN content of x > 0.9, a morphotropic phase boundary (MPB) between the tetragonal and orthorhombic phases was found in the 0.015NBT–0.965NKN–0.02BT ceramics, and the piezoelectric properties were enhanced (d33 = 135 pC/N, kp = 29%). The piezoelectric properties of this system were closely related to its crystal structure.

Phase transition, dielectric and piezoelectric properties of NaNbO3–Bi0.5Li0.5TiO3 lead-free ceramics

2012 ◽  
Vol 12 (6) ◽  
pp. 1523-1528 ◽  
Author(s):  
Lingling Fu ◽  
Dunmin Lin ◽  
Qiaoji Zheng ◽  
Xiaochun Wu ◽  
Lang Wu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Dielectric And Piezoelectric Properties

Investigation of the Morphotropic Phase Boundary (MPB) of (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3

2014 ◽  
Vol 787 ◽  
pp. 242-246
Author(s):  
Rui Lin Wu ◽  
Tomoaki Karaki ◽  
Jiang Tao Zeng ◽  
Liao Ying Zheng ◽  
Wei Ruan ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Reaction Method ◽  
Dielectric And Piezoelectric Properties

Lead-based piezoelectric ceramics have excellent piezoelectric properties with the compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB)[1,2]. In these materials, the dielectric and piezoelectric properties show the maximal values at MPB. For lead-free piezoelectric ceramics, finding the MPB area is a promising way to improve their properties. In this paper, the (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3 lead-free piezoelectric ceramics were prepared by solid-state reaction method, and their piezoelectric properties and dielectric properties were investigated. With the increase of KNLN content, the crystal structure changed from rombohedral phase to tetragonal phase, thus existed a MPB[3,4] between rombohedral and tetragonal phase. At room temperature, the specimen with the composition at MPB (x=0.93, y=0.01) shows the optimal piezoelectric properties (d33=225pC/N and kp=45%), which indicates that this material is a potential lead-free piezoceramic.

Hydrothermal epitaxy of lead free (Na,K)NbO3-based piezoelectric films

2013 ◽  
Vol 1547 ◽  
pp. 45-52
Author(s):  
Albertus D. Handoko ◽  
Gregory K. L. Goh
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Phase Boundary ◽  
Hydrothermal Method ◽  
Morphotropic Phase Boundary ◽  
Solid Solutions ◽  
Lead Zirconate Titanate ◽  
Piezoelectric Properties ◽  
Lead Zirconate ◽  
Lead Free

ABSTRACTLead free niobate solid solutions can exhibit piezoelectric properties comparable to that of lead zirconate titanate piezoelectrics in the vicinity of its morphotropic phase boundary (MPB). Here we describe how (Na,K)NbO3 and (Na,K)NbO3-LiTaO3 solid solution thin films can be grown epitaxially by the hydrothermal method at temperatures of 200 °C or below in water and be made ferro- and piezoelectrically active by a simple 2 step post growth treatment.

scholarly journals Dielectric and piezoelectric perfomance of lead-free ceramics of boron sodium gadolinate niobate at morphotropic phase boundary

2020 ◽  
Vol 10 (04) ◽  
pp. 2050014
Author(s):  
Nissamuddeen Kunnath ◽  
Jacob Philip
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Lead Free ◽  
Sintered Ceramic ◽  
Commercial Grade ◽  
Uniform Microstructure ◽  
Lead Free Ceramics ◽  
Sem Imaging ◽  
Near Future ◽  
Dielectric And Piezoelectric Properties

New lead-free piezoceramic nanocomposites of Boron Sodium Gadolinium Niobate (BNGN), with general formula (1[Formula: see text][Formula: see text][Formula: see text][Formula: see text][Formula: see text][Formula: see text][Formula: see text]NbO3, exhibiting a Morphotropic Phase Boundary (MPB), have been synthesized following hydrothermal method followed by solid state sintering. The occurrence of MPB at the composition with [Formula: see text], at which rhombohedral and monoclinic phases are found to coexist, has been confirmed using powder XRD. This accounts for the occurrence of large remnant polarization when the sintered ceramic pellets are subjected to electric poling at 2KV/mm. Uniform microstructure of various compositions is confirmed by SEM imaging. Dielectric and piezoelectric properties of the samples are found to be comparable to those of commercial grade PZT. At the MPB, the [Formula: see text] coefficient is found to be 556 pC/N, which is close to that of commercial grade PZT, which makes BNGN a promising material to substitute lead containing PZT in the near future.

Properties of 0.96(Bi0.5Na0.5)TiO3-(0.04-x)BaTiO3-xLiNbO3 Lead-Free Piezoceramics Near Morphotropic Phase Boundary

2015 ◽  
Vol 0 (0) ◽  
Author(s):  
Ya-Ting Zhang ◽  
Ying Yang ◽  
Yi-Ping Wang ◽  
Jing Chen
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Dielectric And Piezoelectric Properties

AbstractThe structure, dielectric and piezoelectric properties of 0.96(Bi

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