Bi(Zn_2/3Nb_1/3)O₃-(K_0.5Na _0.5)NbO₃ high-temperature lead-free ferroelectric ceramics with low capacitance variation in a broad temperature usage range

The xBi(Zn_2/3Nb_1/3)O₃-(1-x)(K _0.5Na_0.5)NbO₃ (abbreviated as xBZN-(1-x)KNN) ceramics have been synthesized using the conventional solid-state sintering method. The phase structure, dielectric properties and "relaxorlike" behavior of the ceramics were investigated. The 0.03BZN-0.97KNN ceramics show a broad and stable permittivity maximum near 2000 and lower dielectric loss (5%) at a broad temperature usage range (100;degdeg) and the capacitance variation (I;circbsubdegesub) is maintained smaller than ±15%. The 0.03BZN-0.97KNN ceramics only possess the diffuse phase transition and no frequency dispersion of dielectric permittivity, which indicates that 0.03BZN-0.97KNN ceramics is a high temperature "relaxorlike" ferroelectric ceramics. These results indicate that 0.03BZN-0.97KNN ceramics are excellent promising candidates for preparing high-temperature multilayer ceramics capacitors.