Abstract
Lead free bulk ceramics manganese doped ceramics (1-x)(K0.5Na0.5)NbO3-xMnO2 (0 ≤ x ≤0.8 mol%, KNN-Mn-x) were prepared by a conventional solid-state sintering technique. Effects of manganese on the phase structure, morphologies and electrical properties of KNN ceramics were investigated. Mn-doped ceramics exhibited good crystallization and improved ferroelectric property. The XRD results showed the single phase perovskite structure was obtained in Mn-doped KNN ceramics. For KNN-Mn-x ceramics with x = 0.4 mol.%, excellent ferroelectric property was obtained: high remanent polarization Pr = 28.3 μC/cm2 and low coercive field Ec = 13.7 kV/cm, which should be attributed to the single phase perovskite structure and the existence of a morphotropic phase boundary (MPB).