Novel thermal‐sensitive properties of NBT‐BZT composite ceramics for high‐temperature NTC thermistors

Abstract We found for the first time that (1 − x ) Na 0.5 Bi 0.5 TiO 3 ‐xBiZn 0.5 Ti 0.5 O 3 (NBT–BZT) composite ceramics showed negative temperature coefficient (NTC) at a high temperature. The NBT–BZT nanopowders were successfully prepared by Pechini method. Their ceramics were sintered at 1100°C. The NBT–BZT ceramic exhibited a good linear relationship between logarithm of electrical resistivity (Inρ) and reciprocal of absolute temperature (1000/T) at 250°C–1050°C. The obtained ρ 600 , ρ 900 , and B 600/900 constants of the NBT–ZBT NTC thermistors are approximately 5.92 × 10 6 to 3.01 × 10 4 Ω cm, 7.03 × 10 3 to 7.60 × 10 2 Ω cm and 2.3 × 10 4 ‐1.3 × 10 4 K, respectively. The electrical characteristics can be tuned to the desired value by changing the Na 0.5 Bi 0.5 TiO 3 content in the compound. The electrical conductivity in these compounds is due to the electron jumps between Ti 3+ and Ti 4+ and oxygen‐ion conductivity. Results demonstrate a tremendous potential of the studied system for perovskite materials with NTC performance.