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The current study investigated the dielectric and electrical properties of BaAl (2−2 x) (Zn 0.5 Ti 0.5) 2 x O 4 ceramics, with x = 0, 0.4%, 0.8%, 1.2% and 1.6%, via impedance spectroscopy. The co-doping of Zn and Ti improved the temperature stability over −100 °C–700 °C of ε r and lowered tan δ due to the electron-pinned defect-dipoles. Effects of oxygen partial pressure on the electrical, dielectric and ferroelectric properties of x = 1.6% ceramic were studied as well. The bulk conductivity of the N 2 –H 2 -sintered and O 2 -sintered samples was attributed to the e ' and h • , respectively. [ABSTRACT FROM AUTHOR]

The structure and dielectric properties of BaAl (2−2 x) (Zn 0.5 Ti 0.5) 2 x O 4 ceramics were investigated. Single-phase solid solutions in space group P6 3 (No. 173) were confirmed when 0% ≤ x ≤ 1.6%. [Zn 0.5 /Ti 0.5 ]3+ averagely occupied four symmetrically inequivalent Al sites, and Al1/(Zn,Ti)–O, Al2/(Zn,Ti)–O and Al3/(Zn,Ti)–O bond lengths increased with increased x. Two dielectric anomalous peaks existed, the first peak referred to second-order ferroelectric transition. Stability was significantly improved by moving the first dielectric abnormal peak from 123 °C to −22 °C due to the lower atomic shift amplitude Δz of B cations along the polar axis. The co-doping of Zn2+ and Ti4+ played a decisive role in realizing an ultrabroad temperature range (−100 °C–700 °C) of stability (−27 ppm/°C ≤ TCC ≤ +10 ppm/°C), which met the conditions of C0G or NP0 multilayer ceramic capacitors (±30 ppm/°C). Superior insulating properties were performed by high resistivity of > 1014 Ω cm. [ABSTRACT FROM AUTHOR]