Investigation of Ga doping for non-stoichiometric sodium bismuth titanate ceramics

• DOI: 10.1007/s10854-021-06158-0
• Publication Date: 2021-05-23T20:02:40Z
• Authors: M. Y. Li; C. He; W. G. Wang; G. L. Hao; X. Y. Li; T. Liu; X. F. Wang; D. Wang
• Keywords: 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 0104 chemical sciences

Abstract The electrical performance of Ga3+ doping Na0.5Bi0.5TiO3-based oxygen ion conductor was studied. The Na0.52Bi0.47Ti1−xGaxO3−δ (x = 0, 0.01, 0.015, 0.02) samples were fabricated by the means of traditional solid-state reaction. The results of AC impedance measurement show that the bulk conductivity of Na0.52Bi0.47Ti1−xGaxO3−δ samples decrease monotonously with the increase of Ga3+ doping. At 673 K, the bulk conductivity of the Na0.52Bi0.47Ti0.98Ga0.02O3−δ sample is 7.19×10− 4 S/cm, which is lower than that of Na0.52Bi0.47TiO3−δ sample under the identical test temperature. The highest total conductivity emerges in the Na0.52Bi0.47Ti0.99Ga0.01O3−δ sample with 1.387×10− 4 S/cm at 623 K for the Ga3+ doping content of 1 mol%, which demonstrate that a slight of Ga3+ doping supports the enhancement of the total conductivity. A relaxation peak was observed in the Na0.52Bi0.47Ti1−xGaxO3−δ compounds. As the Ga3+ ions were introduced into the Na0.52Bi0.47TiO3−δ compound, there is an increasing trend of the relaxation activation energy educed by the internal friction test. In addition, the oxygen relaxtion height of Na0.52Bi0.47Ti1−xGaxO3−δ samples decreases along with the introduction of the Ga3+ doping, suggesting that the introduction of the Ga3+ leads to the decrease of mobile oxygen vacancy .