Characterization of lead-free alkali niobate piezoceramics by the Inverse Method

摘要: Material constants of manganese-doped sodium potassium niobate (NKN) were characterized by the Inverse Method, which provides material minimizing deviations between frequency-resolved electrical impedance measurements and finite element simulations. Impedance curves two different types ceramic samples featuring same geometric shape but polarization directions, measured in temperature range −25 °C to 150 °C. at each using curves. As a result, an anisotropic decrease elastic stiffness was observed with increasing temperature. It can be assumed that this dependency is attributed orthorhombic-tetragonal phase transition. Furthermore, maximum loss factor obtained 75 °C, caused minimum all resonance-antiresonance pairs