Composition-Dependent Dielectric and Piezoelectric Properties of Na1-zKzNbO3 Ceramics

Abstract

Sodium potassium niobate, Na_1-zK_zNbO₃, is a ceramic material that exhibits dielectric and piezoelectric properties, which can be tuned by changing the composition of the material. The dielectric properties of Na_1-zK_zNbO₃ ceramics are characterized by a high dielectric constant and low loss, which makes them useful for applications in capacitors, filters, and resonators. Pellets of Na_1-zK_zNbO₃ (0.120 ≤ z ≤ 0.210) were prepared by the solid-state reaction technique. The structural and morphological study was carried out on the prepared compositions at room temperature (RT). A Piezoelectric indirect constant (d₃₃*) was obtained for the prepared compositions. Additionally, dielectric measurements were performed at frequencies 10-1000 kHz, from ambient temperature to 500 ^°C. For the prepared compositions with z = 0.175, a break in the XRD peak shifting patterns was observed, and the average grain size was calculated at 2.044 ± 0.3 µm. Also, the maximum indirect piezoelectric constant (d₃₃*) was observed for z = 0.175 among the prepared compositions. For the prepared compositions, compositions with z = 0.140 showed the highest dielectric constant (peak value 1486, 385 ^°C). Among the prepared samples, dielectric constant (ε), loss tangent (tan δ) and electric conductivity (σ) were found to be minimum for the composition with z = 0.175 at all the measured frequencies. Anomalous dielectric, piezoelectric and structural properties are evident for the samples with z = 0.175 among the prepared samples. Overall, the composition-dependent dielectric and piezoelectric properties of Na_1-zK_zNbO₃ ceramics make them promising materials for use in various electronic and sensing applications where high-performance dielectric and piezoelectric materials are required.