Sm2O3掺杂(Ba0.7Ca0.3)TiO3-Ba(Zr0.2Ti0.8)O3无铅压电陶瓷的制备与性能

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崔业让, 刘心宇, 袁昌来, 翟霞, 胡耀斌, 李若雯. Sm₂O₃掺杂(Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃无铅压电陶瓷的制备与性能 . 无机材料学报, 2012, 27(7): 731-734
CUI Ye-Rang, LIU Xin-Yu, YUAN Chang-Lai, ZHAI Xia, HU Yao-Bin, LI Ruo-Wen. Preparation and Properties of Sm₂O₃ Doped (Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃ Lead-free Piezoelectric Ceramics . Journal of Inorganic Materials, 2012, 27(7): 731-734 复制到剪切板

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Sm₂O₃掺杂(Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃无铅压电陶瓷的制备与性能

崔业让¹, 刘心宇^1,², 袁昌来^1,², 翟霞¹, 胡耀斌¹, 李若雯¹

1. 桂林电子科技大学广西信息材料重点实验室, 桂林 541004

2. 中南大学材料科学与工程学院, 长沙 410083

刘心宇, 教授. E-mail:yyxyl@163.com

崔业让(1986-), 男, 硕士研究生. E-mail:cuicui612@126.com

基金:广西省自然科学基金(2010GXNSFD013007); 广西信息材料重点实验室主任基金(桂科能0710908-15-Z);

摘要

采用固相合成法制备了Sm₂O₃掺杂的(Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃(BCZT)无铅压电陶瓷. 借助XRD、SEM等手段对该陶瓷的显微结构与电性能进行了研究. 结果表明, Sm₂O₃的掺杂降低了BCZT无铅压电陶瓷的烧结温度并使居里温度点T_c从85℃提高到95℃. 当Sm₂O₃掺杂量为0.02wt%~0.1wt%时, 样品具有典型ABO₃型钙钛矿结构. Sm₂O₃掺杂量为0.02wt%时, 所得陶瓷样品具有最优综合电性能, 其压电常数d₃₃、机电耦合系数k_p、机械品质因子Q_m、介电损耗tanδ和介电常数ε_r分别为590 pC/N、0.52、43、1.3%和3372.

关键词: 无铅压电陶瓷; Sm₂O₃; 压电性能; 钙钛矿

中图分类号:TQ174 文献标志码:A 文章编号:1000-324X(2012)07-0731-04

Preparation and Properties of Sm₂O₃ Doped (Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃ Lead-free Piezoelectric Ceramics

CUI Ye-Rang¹, LIU Xin-Yu^1,², YUAN Chang-Lai^1,², ZHAI Xia¹, HU Yao-Bin¹, LI Ruo-Wen¹

1. Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China

2. College of Material Science and Engineering, Central South University, Changsha 410083, China

Fund:Natural Science Foundation of Guangxi Province(2010GXNSFD013007); The Information Materials Key Laboratory Foundation of Guangxi (0710908-15-Z)

Abstract

Sm₂O₃ doped (Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃ (BCZT) lead-free piezoelectric ceramics were prepared by solid state synthesis method. The microstructure and electrical properties of prepared ceramics were investigated by XRD, SEM and other techniques. The results demonstrate that Sm₂O₃ doping reduces sintering temperature of BCZT lead-free piezoelectric ceramics and increases the Curie temperatureT_c from 85℃ to 95℃. BCZT ceramics doped with 0.02wt%-0.1wt% Sm₂O₃ possess a typical ABO₃ type perovskite structure.With the doping of 0.02wt% Sm₂O₃, the BCZT ceramics show the optimum electrical properties, and its piezoelectric constantd₃₃, electromechanical coupling factork_p, mechanical quality factorQ_m, dielecteic loss tanδ and relative dielectric constantε_r reach 590 pC/N, 0.52, 43, 1.3% and 3372, respectively.

Keyword: lead-free piezoelectric ceramics; Sm₂O₃; piezoelectric property; perovskite

Show Figures

压电陶瓷可以实现机械能和电能相互转换, 广泛应用于机械、电子、通讯等领域^{[ 1]}. 长期以来, 锆钛酸铅(PZT)材料在压电陶瓷的发展与应用过程中一直占主导地位, 但PZT基陶瓷是一种环境污染严重的材料. 随着全社会对环保问题的重视, 寻找能够代替PZT的无铅压电材料成为电子材料领域的紧迫任务之一^{[ 2, 3]}.

钙钛矿结构无铅压电陶瓷因具有相对较好的压电性能已成为人们研究的焦点之一^{[ 4, 5, 6, 7]}, 其中由REN等^{[ 6]}发现的(Ba_0.7Ca_0.3)TiO₃- xBa(Zr_0.2Ti_0.8)O₃无铅压电陶瓷体系因其 d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[ 6, 7, 8, 9, 10, 11, 12, 13]}. 但是, 用传统工艺烧结的BCZT陶瓷烧结温度高达1540℃^{[ 11]}, 如何提高致密度,改善压电性能成为(Ba_0.7Ca_0.3)TiO₃- xBa(Zr_0.2Ti_0.8)O₃体系改性研究的重要内容.

大量研究表明, 稀土元素的掺杂能够很好地提高压电陶瓷的致密度和改善其压电性能. Gao等^{[ 14]}采用CeO₂对KNN基无铅压电陶瓷掺杂的研究表明, CeO₂的引入提高了KNN基陶瓷体系的致密度和压电性能. 郑严艳^{[ 15]}采用Sm₂O₃对BNT基压电陶瓷掺杂的研究表明, Sm₂O₃掺杂不仅能够降低陶瓷试样的介电损耗, 而且能提高陶瓷试样的致密度和压电性能. 本工作采用Sm₂O₃掺杂(Ba_0.7Ca_0.3)TiO₃- Ba(Zr_0.2Ti_0.8)O₃(BCZT)制备无铅压电陶瓷, 并研究了Sm₂O₃的引入对BCZT陶瓷的晶相、显微结构和压电、介电等性能的影响.

1 实验

用固相合成法制备(Ba_0.7Ca_0.3)TiO₃- Ba(Zr_0.2Ti_0.8)O₃- xSm₂O₃无铅压电陶瓷, 以充分干燥的分析纯BaCO₃(≥99.0%)、CaCO₃(≥99.0%)、TiO₂(≥99.0%)、ZrO₂(≥99.0%)为原料. 按化学式(Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃的理论组成计算配方. 原料以无水乙醇为球磨介质球磨24 h; 干燥后过147 μm筛, 在1200~1250℃下保温2 h. 合成好的粉料掺入Sm₂O₃(0.02wt%、0.04wt%、0.06wt%、 0.08wt%、0.1wt%后再次球磨8 h, 烘干后加入适量的聚乙烯醇(PVA)溶液进行造粒; 然后, 干压成型为φ15 mm×1.5 mm的圆片备用. 烧结时样品在600℃排胶2 h, 然后以200℃/h速度升温至1350℃保温烧结4 h, 随炉冷却. 样品被银电极, 在30~50℃的硅油内按3~4 kV/mm加直流电压极化 10 min, 放置24 h后测量其性能.

采用ZJ-3AN型准静态 d₃₃测量仪测量样品的压电常数 d₃₃; 采用 D8-2-ADVANCED型X衍射仪(BRUKER AXS, German)测定样品的XRD图谱; 采用JSM-5610 LV型SEM(JEOL, Japan)观察样品的微观形貌; 采用 Agilent 4294A精密阻抗分析仪测量陶瓷的介电容量、径向模谐振频率、反谐振频率、阻抗和介电温谱等.

2 结果分析与讨论

2.1 物相分析

图1为掺杂不同Sm₂O₃的BCZT陶瓷样品的XRD图谱. 从图l(a)可以看到, 各组分样品均形成了典型的ABO₃型钙钛矿结构, 没有明显的第二相生成. 表明Sm₂O₃完全扩散固溶进入BCZT陶瓷晶格中. 图1(b)显示了2 θ为45°附近的XRD图谱, 由衍射峰(002)/(200)可以得出, 该体系陶瓷样品由四方结构向准立方结构转变^{[ 6]}, 在0.02wt%~0.04wt%范围内出现准同型相界(MPB). 此外, 随着Sm³⁺含量的增加到0.1wt%时, 陶瓷样品的衍射峰明显向高角度移动. Sm³⁺半径为0.096 nm、A位的Ca²⁺半径0.134 nm、B位的Zr⁴⁺半径0.072 nm. 从离子半径相近角度看, Sm³⁺更容易进入B位与Zr⁴⁺发生取代反应. 由于Sm³⁺半径比Zr⁴⁺半径大, 导致晶格膨胀, 引起BCZT陶瓷样品四方、准立方相界转变和衍射峰的偏移. 当Sm³⁺含量增加到0.1wt%时出现异常. 其引起原因有待于进一步研究.

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	图1 掺杂不同Sm₂O₃的BCZT陶瓷样品的XRD图谱Fig. 1 XRD patterns of BCZT ceramic samples doped with different contents of Sm₂O₃

2.2 显微结构分析

图2为掺杂不同Sm₂O₃的BCZT陶瓷样品的SEM照片, 从图中可以看出, 随着Sm₂O₃掺杂量的增加, 样品的晶粒逐渐细化. 掺杂量 x=0.02wt%时,晶粒大小较均匀, 而当掺杂量继续增加到0.1wt%时,出现许多尚未充分生长的小晶粒. 这是因为添加少量Sm³⁺增加了晶格中的氧空位, 促进烧结使晶粒增大. 但加入过量的Sm₂O₃会使Sm³⁺堆积在晶界处则会阻止晶粒的长大.

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	图2 掺杂不同Sm₂O₃的BCZT陶瓷样品的SEM照片(a) 0.02wt%; (b) 0.04wt%; (c) 0.06wt%; (d) 0.08wt%; (e) 0.1wt%Fig. 2 SEM images of BCZT ceramic samples doped with different contents of Sm₂O₃

2.3 压电性能分析

图3为掺杂不同Sm₂O₃的BCZT陶瓷样品的压电性能, 从图中可以看出, 随着Sm₂O₃掺杂量的增加, 压电常数 d₃₃和机电耦合系数 k_p大致都下降. 当掺杂量为0.02wt%时, 压电常数 d₃₃和机电耦合系数 k_p达到最优值, 分别为590 pC/N和0.52. 而机械品质因子 Q_m则相反, 随着Sm₂O₃掺杂量增加不断上升, 从43增加到89. 根据图1(b)可知, Sm₂O₃掺杂量在0.02wt%~0.04wt%范围内出现准同型相界(MPB), 当少量的Sm³⁺取代Zr⁴⁺时, 由于价态不同而产生氧空位, 有利于晶格内电畴的转向, 进而提高压电性能, 随着Sm₂O₃的不断增加, Sm³⁺进入晶界, 阻止晶粒的生长使晶粒生长不均匀; 晶粒变小会使畴壁运动困难, 恶化压电性能, 表现为压电系数 d₃₃和 k_p降低. 这说明Sm₂O₃的引入对BCZT陶瓷体系的压电性能的影响很大.

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	图3 掺杂不同Sm₂O₃的BCZT陶瓷样品的压电性能Fig. 3 Piezoelectric properties of BCZT ceramic samples doped with different contents of Sm₂O₃

2.4 介电温谱分析

图4为掺杂不同Sm₂O₃的BCZT陶瓷样品在10 kHz下的介电温谱, 由图看出, 随着Sm₂O₃掺杂量的增加, 陶瓷样品的居里温度 T_C从85℃^{[ 11]}提高到95℃. Sm³⁺半径(0.096 nm)和B位的Zr⁴⁺半径(0.072 nm)相近,发生取代反应, 由于Sm³⁺半径比Zr⁴⁺半径大,导致晶格膨胀, 加上Sm³⁺取代Zr⁴⁺产生氧空位, 氧空位浓度的增加使居里温度 T_C提高. 这说明掺杂Sm₂O₃可以提高BCZT陶瓷的居里温度.

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	图4 掺杂不同Sm₂O₃的BCZT陶瓷样品在10 kHz下的介电温谱Fig. 4 Dielectric temperature spectra of BCZT ceramic samples doped with different contents of Sm₂O₃at 10 kHz

2.5 介电常数和介电损耗分析

图5为掺杂不同Sm₂O₃的BCZT陶瓷样品在 1 kHz下的介电常数和介电损耗. 从图中可以看出陶瓷样品的介电损耗tan δ和介电常数 ε_r随着Sm₂O₃掺杂量增加先增加后减小, 并在掺杂量为0.02wt%时达到最优值, 分别为1.3%和3372. 结合图2可以看出, Sm₂O₃的引入具有促进晶粒生长的作用, 使陶瓷内部空隙减少, 结构更加致密, 可以有效降低本体系陶瓷样品的介电损耗和提高其介电常数.

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	图5 掺杂不同Sm₂O₃的BCZT陶瓷样品在1 kHz下的介电常数和介电损耗Fig. 5 Dielectric constant and dieelectric loss of BCZT ceramic samples doped with different contents of Sm₂O₃at 1 kHz

3 结论

1) 采用固相合成法制备了致密的Sm₂O₃掺杂(Ba_0.7Ca_0.3)TiO₃-Ba(Zr_0.2Ti_0.8)O₃无铅压电陶瓷.

2) 陶瓷样品组成均具典型的ABO₃型钙钛矿结构; Sm₂O₃的掺杂对陶瓷显微组织影响较大, 总体上随着Sm₂O₃掺杂量的增加, 陶瓷晶粒随之细化.

3) 引入Sm₂O₃使BCZT陶瓷样品烧结温度从1540℃降到1350℃; 居里温度点 T_c从85℃提高到了95℃.

4) 陶瓷样品的综合电性能在 x=0.02wt％时达到最优: d₃₃ =590 pC/N, k_p =0.52, Q_m=43, tan δ=1.3%, ε _r=3372.

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1999

0.0

... 压电陶瓷可以实现机械能和电能相互转换, 广泛应用于机械、电子、通讯等领域^[1] ...

2006

0.531

1.106

Journal of Inorganic Materials. 2006, 21(6):1281-1291 DOI:10.3724/SP.J.1077.2006.01281

Researches and developments of (Na_0.5K_0.5)NbO₃-based lead-free piezoelectric ceramics

(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, 710072, China; 2. Electronic Materials Research Laboratory, Key Laboratory of Educational Ministry, Xi’an Jiaotong University, Xi’an 710049, China; 3. The College of Science, Air Force Engineering University, Xi’an, 710051, China)

Lead free piezoelectric ceramics with perovskite structure have attracted considerable attention as new piezoelectric materials because of their good piezoelectric properties. In this paper, The research progress and trend of (Na_0.5K_0.5)NbO₃-based ceramics were summarized and reviewed with emphasizes on the addition of new compositions and sintering aids, ions substitution and processing techniques. The future research works for the developments of (Na_0.5K_0.5)NbO₃-based lead free piezoelectric ceramics were also suggested.

由于钙钛矿结构无铅压电陶瓷具有高的压电性能, 已成为无铅压电陶瓷研究的热点. 本文综述了钙钛矿结构无铅压电陶瓷 (Na_0.5K_0.5)NbO₃的研究进展和趋势. 重点从添加第二组元、添加助烧剂、取代改性和制备方法四个方面, 归纳和分析了 (Na_0.5K_0.5)NbO₃基无铅压电陶瓷的研究开发进展, 并对 (Na_0.5K_0.5)NbO₃基无铅压电陶瓷今后的研究和发展提出一些建议.

... 随着全社会对环保问题的重视, 寻找能够代替PZT的无铅压电材料成为电子材料领域的紧迫任务之一^[2,3] ...

2004

38.597

0.0

... 随着全社会对环保问题的重视, 寻找能够代替PZT的无铅压电材料成为电子材料领域的紧迫任务之一^[2,3] ...

2009

2.821

0.0

Scripta Mater. 2009, 60(10):909-912 DOI:10.1016/j.scriptamat.2009.02.017

Phase structures and electrical properties of new lead-free Na_0.5K_0.5NbO₃-LiSbO₃-BiFeO₃ ceramics

(1 − x)(0.95Na_0.5K_0.5NbO₃–0.05LiSbO₃)–xBiFeO₃ solid-solution piezoelectric ceramics have been fabricated by conventional ceramic processing. A morphotropic phase boundary (MPB) between orthorhombic and tetragonal ferroelectric phases was identified around x = 0.004. The ceramics near the MPB exhibit good electrical properties (d₃₃ = 260 pC/N⁻¹, k_p = 51.5%, T_c = 365 °C, ρ = 4.51 g cm⁻³ and tan θ = 2.00%). The results indicate that this ceramic is a promising lead-free piezoelectric material.

... 钙钛矿结构无铅压电陶瓷因具有相对较好的压电性能已成为人们研究的焦点之一^[4,5,6,7], 其中由REN等^[6]发现的(Ba_{0 ...}

2008

1.846

0.0

... 钙钛矿结构无铅压电陶瓷因具有相对较好的压电性能已成为人们研究的焦点之一^[4,5,6,7], 其中由REN等^[6]发现的(Ba_{0 ...}

2009

7.943

0.0

... 钙钛矿结构无铅压电陶瓷因具有相对较好的压电性能已成为人们研究的焦点之一^[4,5,6,7], 其中由REN等^[6]发现的(Ba_{0 ...}

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

... 附近的XRD图谱, 由衍射峰(002)/(200)可以得出, 该体系陶瓷样品由四方结构向准立方结构转变^[6], 在0 ...

2010

2.107

0.0

... 钙钛矿结构无铅压电陶瓷因具有相对较好的压电性能已成为人们研究的焦点之一^[4,5,6,7], 其中由REN等^[6]发现的(Ba_{0 ...}

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2010

2.39

0.0

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2010

2.224

0.0

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2010

0.0

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2011

2.36

0.0

J. Eur. Ceram. Soc. 2011, 31(11):2005-2012 DOI:10.1016/j.jeurceramsoc.2011.04.023

Enhanced piezoelectric properties of (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1)O₃ lead-free ceramics by optimizing calcination and sintering temperature

Abstract

Lead-free (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1)O₃ (BCTZ) piezoelectric ceramics were prepared by conventional oxide-mixed method at various calcination and sintering temperatures. Both calcination and sintering temperatures have a significant effect on the density and grain size, which are closely related with piezoelectric and other properties of ceramics. The calcination temperature has a great influence on the grain boundary, which also plays an important role in piezoelectric properties. With increased calcination and sintering temperature, the ferroelectric and piezoelectric properties have enhanced significantly. The BCTZ ceramics calcined at 1300 °C and sintered at 1540 °C exhibit optimal electrical properties: d₃₃ = 650 pC/N, d₃₁ = 74 pC/N, k_p = 0.53, k_t = 0.38, k₃₁ = 0.309, , ?_r = 4500, P_r = 11.69 μC/cm², which is a promising lead-free piezoelectric candidate.

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

... 但是, 用传统工艺烧结的BCZT陶瓷烧结温度高达1540℃^[11], 如何提高致密度,改善压电性能成为(Ba_{0 ...}

... 4 介电温谱分析图4为掺杂不同Sm₂O₃的BCZT陶瓷样品在10 kHz下的介电温谱, 由图看出, 随着Sm₂O₃掺杂量的增加, 陶瓷样品的居里温度T_C从85℃^[11]提高到95℃ ...

2011

0.531

1.106

Journal of Inorganic Materials. 2011, 26(6):655-658 DOI:10.3724/SP.J.1077.2011.00655

Study of structure and dielectric properties of (Ba₁-_xCa_x)(Ti_0.82Zr_0.18)O₃ ceramics

(College of Materials Science & Engineering, Xihua University, Chengdu 610039, China)

(Ba_1-xCa_x)(Ti_0.82Zr_0.18)O₃(BCZT, 0≤x≤0.26) ceramics was prepared by a solid phase reaction. The effect of Ca²⁺ doping on the microstructure and dielectric properties of the ceramics was studied. Results showed that the solid solubility lay around x=0.16 for BCZT ceramics while the second phase was observed. The value of c/a changed as the U-type curve with the variation of the Ca²⁺, and the minimum of the c/a was 1.00276 at x=0.06. It was found that Ca²⁺ ion substitution can be almost incorporated into the A site by the calculation of the tolerance factor and lattice constant. With increasing Ca²⁺ ion content, the grain size was decreased. The Curie temperature was shifted to low temperature, and the εr-T peak was decreased and broaden. The relaxor characteristics were obtained while Ca²⁺ ion content was further increased.

采用固相反应法制备了(Ba_1-xCa_x)(Ti_0.82Zr_0.18)O₃(BCZT, 0≤x≤0.26)陶瓷, 研究了Ca²⁺掺杂对BCZT陶瓷微观结构和介电性能的影响. 结果表明: 当Ca²⁺掺杂量为0.16时, BCZT陶瓷出现第二相CaTiO₃, 其四方率c/a随Ca²⁺掺杂量的增加先减小再增大, 当Ca²⁺掺杂量为0.06时达到最小值1.00276. 通过容差因子和晶格参数的计算确认了Ca²⁺已进入到A位; 随Ca²⁺掺杂量的增加, 晶粒得到细化, 居里温度向低温方向移动, 介电峰被压低并展宽, 且逐渐呈现铁电弥散性.

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2009

2.36

0.0

J. Eur. Ceram. Soc. 2009, 29(15):3235-3242 DOI:10.1016/j.jeurceramsoc.2009.06.034

Dielectric and piezoelectric properties of (Ba_0.95Ca_0.05)(Ti_0.88Zr_0.12)O₃ ceramics sintered in a protective atmosphere

Abstract

(Ba_0.95Ca_0.05)(Ti_0.88Zr_0.12)O₃ (BCTZ) ceramics have been produced in a protective atmosphere of industrial N₂ gas for potential piezoelectric applications. For comparison, the ceramics were also sintered at 1200–1400 °C in air. The results revealed that the reducing atmosphere of pO₂ = 5 × 10² Pa had no substantial effect on the phase structure or the microstructure of the BCTZ ceramics. The XRD patterns suggested a tetragonal to pseudocubic phase transition at sintering temperatures above 1300 °C in both atmospheres. The nitrogen-sintered BCTZ samples had higher dielectric constants ?_r but lower electromechanical coupling coefficients k_p than the air-sintered samples. The piezoelectric constant d₃₃ for the BCTZ ceramics was not significantly influenced by the reducing atmosphere of pO₂ = 5 × 10² Pa. The correlation of dielectric and piezoelectric properties of the BCTZ ceramics with the sintering temperature was explained based on a competing mechanism between phase structure and microstructure.

... 8)O₃无铅压电陶瓷体系因其d₃₃高达620 pC/N以上、介电损耗小、介电常数高等优点, 受到广泛关注^{[6,7,8,9,10,11,12,13]} ...

2009

2.163

0.0

J. Mater. Sci. 2009, 44(10):2466-2470 DOI:10.1007/s10853-009-3314-1

Microstructure, electrical properties of CeO₂-doped (K_0.5Na_0.5)NbO₃ lead-free piezoelectric ceramics

1.The Hong Kong Polytechnic University Department of Applied Physics and Materials Research Centre Kowloon Hong Kong, China

CeO₂-doped K_0.5Na_0.5NbO₃ lead-free piezoelectric ceramics have been fabricated by a conventional ceramic fabrication technique. The ceramics retain the orthorhombic perovskite structure at low doping levels (<1 mol.%). Our results also demonstrate that the Ce-doping can suppress the grain growth, promote the densification, decrease the ferroelectric–paraelectric phase transition temperature (T _C), and improve the dielectric and piezoelectric properties. For the ceramic doped with 0.75 mol.% CeO₂, the dielectric and piezoelectric properties become optimum: piezoelectric coefficient d ₃₃ = 130 pC/N, planar electromechanical coupling coefficient k _p = 0.38, relative permittivity ε_r = 820, and loss tangent tanδ = 3%.

... Gao等^[14]采用CeO₂对KNN基无铅压电陶瓷掺杂的研究表明, CeO₂的引入提高了KNN基陶瓷体系的致密度和压电性能 ...

2007

0.0

... 郑严艳^[15]采用Sm₂O₃对BNT基压电陶瓷掺杂的研究表明, Sm₂O₃掺杂不仅能够降低陶瓷试样的介电损耗, 而且能提高陶瓷试样的致密度和压电性能 ...