Sintering effect on electrical properties and morphology of lead-free Na0.92k0.08NbO3 ceramics

Abstract

Sodium potassium niobate (NKN) powders were synthesized by the solid-state reaction method. The NKN ceramics for composition Na0.92K0.08NbO3 (NKN) were then fabricated by a two-step sintering technique. The effects of the two-step sintering on the properties of the ceramics were investigated. The pure phase NKN was achieved for all sintering temperatures of 1100, 1150, 1200 and 1250°C. The observed change in the microstructure indicates that the grain size increases with the increasing sintering temperatures. Also, the two-step sintering technique produced a higher value of K/(K+Na) weight-% ratio and peak dielectric constant for sintering temperatures 1100, 1150 and 1200°C. However, further increasing of the sintering temperatures at 1250°C, reduces the K/(K+Na) weight-% ratio and the peak dielectric constant (єc).

Keywords

• two-step sintering
• k/(k+na) weight-
• ratio
• dielectric properties and grain size