Large strain of temperature insensitive in (1–x)(0.94Bi0.5Na0.5TiO3–0.06BaTiO3) –xSr0.7La0.2TiO3 lead-free ceramics. Issue 10 (July 2018)

• Record Type: Journal Article
• Authors: Zhao, Nianshun; Fan, Huiqing; Ma, Jiangwei; Ren, Xiaohu; Shi, Yungui; Zhou, Yunyan
• Is Part Of: Ceramics international. Volume 44:Issue 10(2018)
• Page Start: 11331
• Page End: 11339
• Publication Date: 2018-07
• Subjects: Lead-free ceramics -- Temperature Insensitivity -- Relaxors -- Strain -- Phase transformations; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.03.182
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Novel (1– x )(0.94Bi0.5 Na0.5 TiO3 –0.06BaTiO3 )– x Sr0.7 La0.2 TiO3 ternary lead-free ceramics (BNBT– x SL, x = 0.00–0.08) were fabricated by the widely used solid-state sintering technique. The crystal phase, microstructure, dielectric relaxation, piezoelectric, and electromechanical properties of each composition were systematically analyzed. It is found that the addition of SL has little effect on the crystal phase and grain morphology, but it can remarkably improved the relaxation property of the ceramic sample and gave rise to favourable dielectric properties in a wide range of temperatures. In addition, as the SL content increases, the ferroelectric to relaxor temperature ( T F-R ) is adjusted to below ambient temperature. More importantly, the decay of ferroelectric phase resulted in a significant increase in strain value: the large strain of 0.5% with normalized strain of 625 pm/V was obtained at 80kv/cm and x = 0.04. Finally, the composition exhibited high strain of temperature insensitivity range from room temperature to 100 °C, the strain value remained above 0.4% and kept within 5%. The results are due to the coexistence of rhombohedral polar-nanoregions (PNRs) and tetragonal PNRs during the relaxor region. This result is of great importance to the developments of temperature-insensitive strain sensors and actuators.