Investigation of piezoelectric properties in manganese doped alkaline niobate-based lead-free piezoceramics

In this work, an attempt is made for improving the piezoelectric properties of a lead-free (Na[Formula: see text]K[Formula: see text]Li[Formula: see text](Nb[Formula: see text]V[Formula: see text]O 3 ceramic system by doping manganese in it. The Rietveld analysis of XRD micrographs of the ceramics indicates the samples crystallizing into 99.86% of orthorhombic phase and very small traces of tetragonal phase around room temperature. The Curie temperature ([Formula: see text]) is hardly affected by the incorporation of Mn[Formula: see text] into the system. At the manganese concentration of 0.02[Formula: see text]wt.%, the ceramic system attains the peak values in its density, dielectric constant at room temperature ([Formula: see text]), planar electromechanical coefficient ([Formula: see text], piezoelectric coefficient ([Formula: see text]), and remnant polarization ([Formula: see text]). The optimum piezoelectric properties of [Formula: see text]% and [Formula: see text] pC/N are observed for this composition. The study reveals that the modification of (Na[Formula: see text]K[Formula: see text]Li[Formula: see text]) (Nb[Formula: see text]V[Formula: see text]O 3 with an appropriate quantity of Mn[Formula: see text] can produce the desired changes in the crystallographic properties and densification so as to eventually improve its piezoelectric properties.