Effects of Ti on dielectric and piezoelectric properties of (Pb0.985La0.01)1+y(Nb1−yTiy)2O6 ceramics

✍ Scribed by Yu Zhang; Peng Liu; Xiao-ming Chen; Jun-lin Wu; Gao-li Men; Hui-xia Jing; Jing-na Yang

• Publisher: Elsevier Science
• Year: 2010
• Weight: 946 KB
• Volume: 31
• Category: Article
• ISSN: 0261-3069
• DOI: 10.1016/j.matdes.2010.05.016

✦ Synopsis

Piezoelectric ceramics (Pb 0.985 La 0.01 ) 1+y (Nb 1Ày Ti y ) 2 O 6 (0 6 y 6 0.1) (PLNT) were fabricated by a conventional solid-state reaction method. The crystal structure and microstructures of specimens were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). All PLNT ceramics sintered at temperatures from 1250 °C to 1290 °C are shown to be a single orthorhombic phase. The formation of orthorhombic phase is promoted by excess PbO existed in the Ti-bearing samples during calcination processing. The increasing of the tolerance factor due to substitution of Ti 4+ for Nb 5+ is also responsible for the stability of orthorhombic phase. The high density of ceramics (relative density >95%) with the equiaxed grains and a minor porosity have been obtained. The measurement of dielectric and piezoelectric properties of PLNT ceramics reveals that Ti reduces the dielectric loss (tan d) and dielectric constant (e r ) of PLNT ceramics, and enhances the piezoelectric constant (d 33 ) and Curie temperature (T c ). The optimum component with y = 0.075 possesses the excellent electrical properties: e r = 182, tan d = 0.0018, d 33 = 84 pC/N and T c = 564 °C.