Enhanced piezoelectricity and transmittance of (1-x)K0.5Na0.5NbO3-x(Ca0.5Sr0.5)(Zn1/3Nb2/3)O3 ceramics

K0.5Na0.5NbO3 is an excellent alternative to lead-based transparent ceramics because of its high Curie temperature, excellent piezoelectric properties and environmental friendliness. Normally, achieving both large piezoelectricity and high transparency seems to be difficult. Here, we developed a solid solution of (1-x)K0.5Na0.5NbO3-xCa0.5Sr0.5Zn1/3Nb2/3O3 to enhance the piezoelectric properties while maintaining a considerably high level of transparency. The x = 0.06 sample exhibits the highest transmittance of 64