The Crystalline Structure and Phase-Transitional Behavior of (Li0.12Na0.88)(Nb1−x%Sbx%)O3 Lead-Free Piezoelectric Ceramics with High Qm
Abstract:Lead-free piezoelectric ceramics with formula (Li0.12Na0.88) (Nb1−x%Sbx%)O3 were prepared by the conventional solid-state reaction method. The effects of Sb5+ doped into (Li0.12Na0.88) NbO3 B site were studied. Within the selected compositional range, all the samples have a single perovskite structure. The crystal structure changed from rhombohedral to orthorhombic at x=1, and from orthorhombic to tetragonal symmetry at x=6. The presence of orthorhombic to tetragonal morphotropic phase boundary was proposed when 3<x<6. By substituting Sb5+ for Nb5+, dielectric property and impedance characteristic were enhanced, but the Curie temperature and the ferroelectricity were decreased. The optimum composition was x=3, for which the maximum value of the mechanical quality factor Qm was as high as 1780, piezoelectric constant d33 and Curie temperature Tc were 45 pC/N and 300°C, respectively.
Document Type: Research Article
Affiliations: College of Materials Science and Engineering, Sichuan University, Chengdu 610064, China
Publication date: September 1, 2010