Investigation of the Structure and Electrical Properties of (K_xNa_0.96−xLi_0.04)(Nb_0.96−yTa_ySb_0.04)O₃ Piezoelectric Ceramics Modified with Manganese

Abstract

The effect of high doping levels of manganese (Mn) on the structure and electrical properties of (KxNa1−x)NbO3 (KNN) ceramics containing Li, Ta, and Sb has been investigated. The samples were measured using synchrotron X‐ray diffraction whereas Rietveld refinement with Fullprof was used to determine the structural information as a function of temperature. Temperature‐dependent dielectric measurement was used to compare the phase transition temperatures. The results show that Mn decreases the temperature range of phase coexistence between the orthorhombic and tetragonal phase from ~180°C to ~120°C. The Curie temperature remained unchanged with Mn addition while the dielectric constant and dielectric loss increased with Mn addition. High amounts of Mn led to a reduction in both piezoelectric and ferroelectric properties. The remnant polarization, remnant strain, and piezoelectric coefficient values decreased from 24 μC/cm2, 0.000824, 338 ± 37 pm/V to 13 μC/cm2, 0,00014 and 208 ± 27 pm/V, respectively for the undoped and 5 mol% Mn‐doped sample.

Enhanced transmittance and piezoelectricity of transparent K0.5Na0.5NbO3 ceramics with Ca(Zn1/3Nb2/3)O3 additives

“…These curves, obtained from different temperatures, overlap into a single curve suggesting a perfect relaxation process and the other factors can be ignored. The relationship between the activation energy (E a ) related with the relaxation process, Boltzmann constant (k), absolute temperature (T), and pre-exponential factor (f 0 ), is given as 39 According to eqn (7), the activation energy (E a ) can be estimated from a straight line plot of ln(f max ) vs. 1000/T. As shown in Fig.…”

“…[1][2][3] They are highly likely to be the key material for light, computer and electronic information technologies and national defense military applications in the future. [4][5][6][7] In addition, most transparent piezoelectric ceramics could be used for energy storage. 8 Aer the discovery of transparency in 0.8(K 0.5 Na 0.5 )NbO 3 -À0.2SrTiO 3 ceramics was reported by Malic et al in 2004, 9 K 0.5 Na 0.5 NbO 3 lead-free transparent piezoelectric materials have attracted the attention of many researchers (the development is shown in Fig.…”

Neutron diffraction study of (KxNa1−x)NbO3-based ceramics from low to high temperatures

“…Several research results on these KNN-based ceramics have been reported. The increase in piezoelectric properties was attributed in part to the coexistence of the orthorhombic and tetragonal phases and has also been investigated with synchrotron X-ray diffraction (Mgbemere, Fernandes et al, 2011;, 2013. According to Akdog an et al (2008) this phase coexistence is expected on the basis of Gibb's phase rule under isothermal and isobaric conditions.…”

Alkali volatilization of (Li,Na,K)NbO₃-based piezoceramics and large-field electrical and mechanical properties

“…Here, Nb was considered a non-volatile ion, so we calculated (Na + K)/Nb ratio. The atomic number ratio of Na/Nb and K/Nb in the as-sintered state was almost the same to the nominal composition, 23) while Na/ Nb and K/Nb slightly decreased by 0.12 and 0.08 in the annealed sample for 8 h. As a result, the atomic number of (Na + K)/Nb in the annealed sample for 8 h was lower than 0.02 from the nominal composition. However, the annealed sample for 2 h showed the opposite behavior.…”