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 0. 5 K 0. 4 8 5 Li 0. 0 1 5) (Nb 0. 9 8 V 0. 0 2) O₃ 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 ( T c ) is hardly affected by the incorporation of Mn 4 + into the system. At the manganese concentration of 0.02 wt.%, the ceramic system attains the peak values in its density, dielectric constant at room temperature ( ε RT ), planar electromechanical coefficient ( k p) , piezoelectric coefficient ( d 3 3 ), and remnant polarization ( P r ). The optimum piezoelectric properties of k p = 4 3 % and d 3 3 = 1 9 3 pC/N are observed for this composition. The study reveals that the modification of (Na 0. 5 K 0. 4 8 5 Li 0. 0 1 5 ) (Nb 0. 9 8 V 0. 0 2) O₃ with an appropriate quantity of Mn 4 + can produce the desired changes in the crystallographic properties and densification so as to eventually improve its piezoelectric properties. [ABSTRACT FROM AUTHOR]