Influence of MoO 3 on electrical and microstructural properties of (K 0.44 Na 0.52 Li 0.04 )(Nb 0.86 Ta 0.10 Sb 0.04 )O 3
Microstructure, piezoelectric properties and dielectric behavior of undoped and MoO 3 -doped lead-free (K 0.44 Na 0.52 Li 0.04 )(Nb 0.86-x Ta 0.10-x Sb 0.04-x )Mo 5/6x O 3 (KNL-NTS) was investigated. Samples were obtained by the conventional solid state reaction. X-ray diffraction (XRD) and Raman spectra revealed the formation of a perovskite phase, together with some minor secondary phase which could be assigned by XRD to K 3 LiNb 6 O 17 . XRD also showed that the perovskite evolved from a tetragonal to orthorhombic symmetry with the increasing of doping amount. This behavior was not observed with the increasing in the sintering time. The temperature dependence on real permittivity (e') revealed the presence of a diffuse phase transition. This behavior was increased with MoO 3 concentration. Also, dielectric relaxation processes were observed at room temperature and were dependent on doping level and sintering time.