Effect of MnO2 doping on piezoelectric, dielectric and ferroelectric properties of PNN–PZT ceramics

Piezoelectric Characteristics of 0.55Pb(Ni1/3Nb2/3)O3-0.45Pb(Zr,Ti)O3 Ceramics with Different MnO2 Concentrations for Ultrasound Transducer Applications

“…The MnO2 doping can affect the PNN-PZT ceramic properties owing to the increase in number of oxygen vacancies generated by the substitutions of the high-valence Ti 4+ and Zr 4+ in the perovskite lattice by the low-valence Mn 2+ and/or Mn 3+ , as mentioned above [4]. The oxygen vacancies improved the mechanical properties (Young's modulus, Qm).…”

“…However, it was decreased at 2 mol%, and then largely increased to the maximum of 21.13 × 10 −3 Vm/N at 3 mol%, as the decrease rate of d33 was smaller than the rate of decrease in ε T 33. Table 2 shows the densities and dielectric, mechanical, and piezoelectric properties of the PNN-PZT samples with different MnO2 contents (0, The MnO 2 doping can affect the PNN-PZT ceramic properties owing to the increase in number of oxygen vacancies generated by the substitutions of the high-valence Ti 4+ and Zr 4+ in the perovskite lattice by the low-valence Mn 2+ and/or Mn 3+ , as mentioned above [4]. The oxygen vacancies improved the mechanical properties (Young's modulus, Q m ).…”

“…Recently, many piezoelectric ceramic compositions of the ternary system have been reported as the ternary system has a larger morphotropic phase boundary (MPB) area than that of a secondary system such as PZT. Lead-based relaxor ferroelectrics have a general formula of Pb(B' B")O 3 (where B' is Mg 2+ , Ni 2+ , Zn 2+ , Fe 3+ , Sc 3+ , In 3+ , Mn 4+ , and Sn 4+ and B" is Nb 5+ , Ta 5+ , Sb 5+ , and W 6+ ) [3,4]. In this ternary system, 0.55Pb(Ni 1/3 Nb 2/3 )O 3 -0.45Pb(Zr,Ti)O 3 (PNN-PZT) has attracted increasing attention owing to its excellent piezoelectric properties.…”

“…Liao et al [13] reported that Fe doping largely reduced tanδ and d 33 , but improved Q m and tetragonality of the 0.35BiScO 3 -0.6PbTiO 3 -0.05Pb(Zn 1/3 Nb 2/3 )O 3 ceramic. Liu et al [4] investigated 0.55Pb(Ni 1/3 Nb 2/3 )O 3 -0.45Pb(Zr 0.3 Ti 0.7 )O 3 (PNN-PZT) with varying MnO 2 additive content and reported high performance (d 33 = 710 pC/N, k p = 0.595, ε r = 3092.25, tanδ = 14.9 × 10 −3 , Q m = 176) at a MnO 2 content of 1 mol%. Table 1 shows piezoelectric ceramic and properties according to doping from references.…”

“…To improve the g 33 values and mechanical properties of the PNN-PZT systems, Mn can be added to selectively improve sensor characteristics. The MnO 2 doping can improve the sinterabilities of lead-based relaxor ceramics owing to the increase in number of oxygen vacancies, generated by the substitutions of the high-valence Ti 4+ and Zr 4+ in the perovskite lattice by the low-valence Mn 2+ and/or Mn 3+ [4]. The oxygen vacancies in the perovskite lattice can promote lattice diffusion, thus assisting the sintering and grain growth [12], as the grain boundary movement is dragged by these defects.…”