Observation of Enhanced Unipolar Strain and Piezoelectric Charge Co-Efficient in K0.5Na0.5NbO3 Simultaneously Doped with Lithium and Antimony

The author reports an enhanced strain and piezoelectric charge coefficient (d(33)*) in lead-free Li-x(K0.5Na0.5)(1-x)(Nb1-ySby)O-3 (x and y = 0,0.02,0.04,0.06) ceramics synthesized through the standard solid-state reaction route. X-ray diffraction analysis of the samples predicts a structural phase transition from orthorhombic to tetragonal with the presence of phase boundary (coexistence of orthorhombic and tetragonal phases) for the Li-0.04(K0.5Na0.5)(0.96)(Nb0.96Sb0.04)O-3 sample supported by Raman spectroscopy. The Li-x(K0.5Na0.5)(1-x)(Nb1-ySby)O-3 (x and y = 0.04) ceramics exhibited enhanced electrical properties with P-s similar to 13 mu C/cm(2), E-c similar to 15 kV/cm, an electrostrictive strain of 0.38% and piezoelectric charge coefficient (d(33)*) of 950 pm/V, making it promising for sensor and actuator applications.