Effect of borax addition on sintering and electrical properties of (K0.5Na0.5) NbO3 lead-free piezoceramics

摘要

Lead-free piezoelectric ceramics (K0.5Na0.5)NbO3 (KNN) doped with borax (Na2B4O7 center dot 10H(2)O) as sintering aid were prepared using conventional ceramic processing. All the ceramics possessed the perovskite structure with orthorhombic symmetry. Results revealed that borax is an effective additive for improving the sinterability and piezoelectric properties of KNN. The KNN with 0.45 wt% borax showed optimal properties as follows: piezoelectric constant d(33)=131.6 pC/N, planar electromechanical coupling coefficient k(p)=34.8%, mechanical quality factor Q(m)= 109, and dielectric loss tan delta=3.80%. Crown Copyright (C) 2015 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.