Work

Effect of Sc3+ doping on the structure and electrical properties of NBT-based oxygen-ion conductor

Year: 2025

Type: article

Abstract: Sc3+ was chosen as the dopant, and two series of samples, Na0.5Bi0.49-xScxTiO3-δ (abbreviated as x Sc-Bi, x = 0–0.05) and Na0.5Bi0.49Ti1-xScxO3-δ (abbreviated as x Sc-Ti, x = 0–0.07), were synthesized via the solid-state method. The influence of Sc3+ doping at distinct lattice sites on the structural, microstructural, and electrical properties of Na0.5Bi0.49TiO3-δ oxygen-ion conductors was systematically investigated. The results reveal that at low doping concentrations (x ≤ 0.02), Sc3+ tends to occupy the Bi3+ sites, while at higher concentrations (x > 0.02), it favors the Ti4+ sites. Sc3+ occupies the Bi3+ sites and inhibits grain growth, while it occupies the Ti4+ sites and facilitates grain growth. In terms of grain conductivity, the x Sc-Bi series samples exhibit superior performance. In terms of grain boundary conductivity, Sc3+ doping significantly reduces grain boundary resistance. At low doping concentrations, the x Sc-Bi series exhibits higher grain boundary conductivity than the x Sc-Ti series; however, at higher concentrations, the x Sc-Ti series outperforms the x Sc-Bi series. Given that grain boundary resistance dominates the total resistance, the x Sc-Ti series samples also exhibit higher total conductivity.

Source: Materials Research Express

DOI: 10.1088/2053-1591/adc785