Modification of strain and piezoelectricity in (K,Na)NbO3-(Bi,Na)HfO3 lead-free ceramics with high Curie temperature

JOURNAL OF ALLOYS AND COMPOUNDS

卷:684

Article

Tao, Hong¹  Wu, Jiagang¹  Wang, Hui² 

[1] Sichuan Univ, Dept Mat Sci, Chengdu 610064, Peoples R China

[2] Sichuan Univ, Analyt & Testing Ctr, Chengdu 610064, Peoples R China

关键词: (K,Na)NbO3;    Bi0.5Na0.5HfO3;    High Curie temperature;    Piezoelectricity;    Strain;   

DOI  :  10.1016/j.jallcom.2016.04.322

来源: Elsevier

【 摘 要 】

In this work, the (1-x)K0.45Na0.55NbO3-xBi(0.5)Na(0.5)HfO(3) lead-free ceramics with a high Curie temperature were prepared by the normal sintering, and the enhancement in strain and piezoelectricity can be attained by tailoring the corresponding compositions. The orthorhombic-tetragonal (O-T) phase coexistence was observed in the ceramics with 0.03 < x < 0.055, and then such a phase boundary was reasonably identified by X-ray diffraction patterns as well as temperature -dependent Raman spectra and dielectric constant. A large piezoelectric constant (d(33)) of similar to 385 pC/N and a high Curie temperature (T-C) of similar to 315 degrees C can be simultaneously induced in the ceramics with x = 0.05. More interestingly, a high unipolar strain of similar to 0.187% was shown in the ceramics with x = 0.04. It was found that the enhanced piezoelectric properties should be attributed to the two phase coexistence as well as enhanced dielectric and ferroelectric properties. We believe that this material is one of the most promising candidates in the field of high-temperature piezoelectrics. (C) 2016 Elsevier B.V. All rights reserved.

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