Phase Analysis of Na_1−xLi_xNbO₃ Ceramics by Neutron and Its Electric Property

Abstract

Crystal structures of the Na_1−xLi_xNbO₃ (x = 0.04, 0.1) ceramic pellets were analyzed using neutron diffraction. The pellets sintered at 1220°C consisted of an orthorhombic (Pb2₁ m) and rhombohedral (R3c) phases. Morphotrophic phase boundary started at x << 0.1. The R3c (4 mass%) coexists with the Pb2₁ m (96 mass%) in the x = 0.04. Neutron analysis results were compared to that of the XRD. The measured P-E characteristics conformed to the analyzed crystal structures. Remanent polarization and coercive field were strongly dependent on sintering temperature (1220∼1260°C) and Li-concentration (x = 0.04∼0.15) respectively.

Keywords:

• Li-doped NaNbO₃
• morphotropic phase boundary
• two phase mixture
• rhombohedral
• orthorhombic

Acknowledgment

Authors are grateful to Min Woo Lee, an undergraduate student, Dept. Materials Sci. & Engineering, Hoseo University for preparing and characterizing samples.