Phase evolution, crystal structure and dielectric behavior of (1 − x)Nd(Zn0.5Ti0.5)O3 + xBi(Zn0.5Ti0.5)O3 compound ceramics

The phase evolution, crystal structure and dielectric properties of (1 − x)Nd(Zn0.5Ti0.5)O3 + xBi(Zn0.5Ti0.5)O3 compound ceramics (0 ≤ x ≤ 1.0, abbreviated as (1 − x)NZT–xBZT hereafter) were investigated. A pure perovskite phase was formed in the composition range of 0 ≤ x ≤ 0.05. The B-site Zn2+/Ti4+ 1:1 long range ordering (LRO) structure was detected by both XRD and Raman spectra in x ≤ 0.05 samples. However, this LRO structure became gradually degraded with an increase in x. The dielectric behaviors of the compound ceramic at various frequencies were investigated and correlated to its chemical composition and crystal structure. A gradually compensated τf value was obtained in (1 − x)NZT–xBZT microwave dielectrics at x = 0.03, which was mainly due to the dilution of dielectric constant in terms of Claussius–Mossotti differential equation.

Research highlights▶ The dielectric properties measured at RF frequency were comparable to those in GHz frequency range. The frequency dispersion behavior was caused by the reversible dipoles and the localized hopping charge carriers. ▶ The compensation mechanism of the temperature coefficient was due to the dilution of dielectric constant.