Phase transition and electrical properties of Bi_0.5(Na_0.8K_0.2)_0.5ZrO₃ modified (K_0.52Na_0.48)(Nb_0.95Sb_0.05)O₃ lead-free piezoelectric ceramics

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• 作者：Baihui Liu ; Yang Zhang ; Peng Li ; Bo Shen ; Jiwei Zhai ; ^{apzhai@tongji.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：KNN-based ceramics ; BNKZ modification ; Multiphase coexistence ; Electrical properties
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：42
• 期：12
• 页码：13824-13829
• 全文大小：2236 K

文摘

In this work, (1−x)(K_0.52Na_0.48)Nb_0.95Sb_0.05O₃−xBi_0.5(Na_0.8K_0.2)_0.5ZrO₃ [abbreviated as (1−x)KNNS−xBNKZ, x=0–0.06] lead-free ceramics were fabricated using solid-state reaction method. The effects of BNKZ contents on the phase structure, piezoelectric and ferroelectric properties were investigated. The phase boundaries including orthorhombic-tetragonal (O-T) and rhombohedral-tetragonal (R-T) multiphase coexistence were identified by XRD patterns and temperature-dependent dielectric constant by adding different content of BNKZ. A giant field induced strain (~0.25%) along with converse piezoelectric coefficient d₃₃^* (~629.4 pm/V) and enhanced ferroelectricity P_r (~38 μC/cm²) were obtained when x=0.02, while the specimen with x=0.03 presented the optimal piezoelectric coefficient d₃₃ of 215 pC/N, due to the O-T or R-T phase coexistence near room temperature respectively. These results show that the introduction of Bi_0.5(Na_0.8K_0.2)_0.5ZrO₃ is a very effective way to improve the electrical properties of (K_0.52Na_0.48)(Nb_0.95Sb_0.05)O₃ lead-free piezoelectric ceramics.