Technology and electrophysical properties of the (K0.44Na0.52Li0.04)(Nb0.9-xTa0.1Sbx)O3 ceramics

Compounds based on potassium sodium niobate (KxNa1-x)NbO3 (KNN) are promising lead-free ferroelectric materials that show good piezoelectric properties. In the present work we report the results of study influence of doping... [ view full abstract ]

Compounds based on potassium sodium niobate (K_xNa_1-x)NbO₃ (KNN) are promising lead-free ferroelectric materials that show good piezoelectric properties. In the present work we report the results of study influence of doping effect of antimony on the technology, microstructure and electrophysical properties of potassium sodium niobate ceramics modified by lithium and tantalum ions (K_0.44Na_0.52Li_0.04)(Nb_0.9-xTa_0.1Sb_x)O₃, in abbreviation KNLNTSbx. The four KNLNTSb ceramic compositions were designed: (i) (K_0.44Na_0.52Li_0.04)(Nb_0.9Ta_0.1)O₃ (for x=0), (ii) (K_0.44Na_0.52Li_0.04)(Nb_0.88Ta_0.1Sb_0.02)O₃ (for x = 0.02), (iii) (K_0.44Na_0.52Li_0.04)(Nb_0.87Ta_0.1Sb_0.03)O₃ (for x = 0.03), and (iv) (K_0.44Na_0.52Li_0.04)(Nb_0.86Ta_0.1Sb_0.04)O₃ (for x = 0.04). All ceramic powders were synthesized by the standard solid-state reaction method from the mixture of oxides and carbonates. Next, the ceramic powders of KNLNTSbx were pressed and sintered by the free sintering method at temperature T_s = 1130°C with the sintering time t_s = 3 h.

The paper presents the technology of ceramic samples and results of apparent density, crystal structure, microstructural and chemical composition tests, as well as measurements of dielectric properties and DC electrical conductivity of the KNLNTSb ceramics. Conducted research proved that suitable doping of the KNN materials improves its sinterability of the ceramic compositions and positively influences on its useful electrophysical properties.