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(Bi0.5Na0.5)TiO3–0.06(BaTiO3)–xCuO (BNT–BT6–xCu) 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∘C, however, the doped system was sintered at 1150∘C, 1100∘C, 1050∘C, 1025∘C, and 975∘C to determine the effect of Cu on the densification process. Therefore, it was obtained that the CuO-doped samples sintered at 1050∘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 (d33).

Keywords

• lead-free piezoelectric
• piezoelectric properties
• solid-state reaction
• cuo dopant