Effect of sintering temperature on the structural and electrical properties of Na_.47K_.47Li_.06NbO₃ ceramics prepared by ceramic technique using high energy ball milling

Abstract

Lead-free lithium doped sodium potassium niobate piezoceramics having the compositional formula Na_.47K_.47Li_.06NbO₃ were synthesized by ceramic technique using high energy ball milling. The compounds were calcined at 850 °C for 3h and sintered at different temperatures viz. 900 °C, 950 °C, 1000 °C, 1050 °C and 1100 °C for 2h. The calcined compositions showed an orthorhombic perovskite phase and on sintering, the phase transformed to tetragonal phase and this tetragonal structure has been observed for sintering temperature up to 1050 °C. Effect of various sintering temperatures on the electrical properties like dielectric constant, dielectric loss and a.c. conductivity were also studied. The results obtained were analyzed and discussed in the paper.

Keywords:

• Piezoceramics
• KNN
• phase transition
• dielectric constant
• A.C. conductivity