Effects of compositional changes on luminescence of lead-free Eu3+-doped K1−xNaxNbO3 piezoelectric ceramics

Abstract

Abstract Eu 3+ -doped lead-free K 1 − x Na x NbO 3 piezoelectric ceramics were synthesized by a conventional solid-state reaction technique. The structure transition related to the monoclinic phase to orthorhombic phase is located in x = 0.50 by measuring the dielectric and piezoelectric constants of the ceramics. Increasing x from 0.42 to 0.56, the photoluminescence peak intensity of red emission at 615 nm decreased firstly and then increases, giving to the extreme point at x = 0.50. The strong photoluminescence dependence on the structure transition was attributed to the high hypersensitivity of Eu 3+ to the changes of lattice environment. The advantages of noncontact, quick response and simple operation make it potential to be used in investigating the compositional changes near the morphotropic phase boundary of lead-free piezoelectric ceramics.