Lead free KNN (K_0·5Na_0·5NbO₃) ceramics was obtained via the conventional solid state sintering technique. The ceramics synthesized was characterized for their phase transition analysis, crystal structure, morphology and electrical properties. The powder X-ray diffraction (XRD) patterns confirmed single phase of KNN with orthorhombic crystal system at room temperature. Scanning electron microscopy (SEM) of the sintered KNN revealed the existence of densification and comparable size of the grains. Two phase transitions were observed in ϵ_r-T graph: orthorhombic to tetragonal at T_O-T (~236 °C) and tetragonal to cubic at T_T-C (~440 °C) for 1 kHz frequency. The decrease in the net polarization of the material with the increase in frequency leads to the decrease in the value of ϵ_r and tanδ. Three characteristic Raman peaks observed at (~262 cm⁻¹, ~617 cm⁻¹ and ~858 cm⁻¹) correlate the structure and ferroelectric properties of KNN materials. These promising outcomes demonstrate that KNN-based lead-free ceramic composition is potential candidate to substitute lead-based materials for various applications.

通过常规的固态烧结技术获得了无铅的KNN（K _0·5 Na _0·5 NbO ₃）陶瓷。对合成的陶瓷进行相变分析，晶体结构，形态和电性能进行了表征。粉末X射线衍射（XRD）图谱证实了室温下具有正交晶系的KNN为单相。烧结KNN的扫描电子显微镜（SEM）揭示了致密化的存在和晶粒大小的可比性。在ϵ _r -T图中观察到两个相变：在T _O-T（〜236°C）下由正交向四方转变，在T _T-C处由四方转变为立方转变（〜440°C），频率为1 kHz。随着频率的增加，材料的净极化强度的减小导致ϵ _r和tanδ值的减小。在（〜262 cm ^-1，〜617 cm ^-1和〜858 cm ^-1）观察到的三个特征拉曼峰与KNN材料的结构和铁电性能相关。这些令人鼓舞的结果表明，基于KNN的无铅陶瓷组合物是潜在替代各种应用的基于铅的材料的候选者。