Influence of CuO addition on dielectric and piezoelectric properties of (Bi0.5Na0.5)TiO3–BaTiO3lead-free piezoceramics

Abstract

Doping effects of CuO on the sintering behavior and electrical properties of 0.94(Bi[Formula: see text]Na[Formula: see text]TiO3–0.06(BaTiO[Formula: see text]–[Formula: see text]CuO (BNT–BT6–[Formula: see text]Cu) lead-free piezoceramic obtained by the conventional solid-state reaction method were investigated. Regarding the undoped system, it is already known that it presents the best densification values when it is sintered at 1150[Formula: see text]C, however, the doped system was sintered at 1150[Formula: see text]C, 1100[Formula: see text]C, 1050[Formula: see text]C, 1025[Formula: see text]C, and 975[Formula: see text]C to determine the effect of Cu on the densification process. Therefore, it was obtained that the CuO-doped samples sintered at 1050[Formula: see text]C presented the highest density values and therefore were the ones chosen to perform the characterization tests together with the undoped system. The samples were characterized using X-ray diffraction (XRD), Raman microspectroscopy, and scanning electron microscopy (SEM) analysis, whereas the ferroelectric and dielectric properties were evaluated by means of ferroelectric hysteresis loops and impedance spectroscopy studies. As a result, the addition of CuO allowed an improvement in sinterability and densification, with the subsequent grain growth, and the improvement of the piezoelectric coefficient ([Formula: see text].