Phase stability and high conductivity of ScSZ nanofibers: effect of the crystallite size

Abstract

10 mol% Sc₂O₃-doped ZrO₂ (10ScSZ) nanofibers were prepared through electrospinning followed by calcination. The phase structures and electrical conductivities of the nanofibers have been investigated as a function of the crystallite size. The cubic (c) phase can be stabilized in 10ScSZ nanofibers when the average crystallite size is smaller than 26 nm. The generated phase stability endows the nanofibers with an enhanced conductivity which increases with the decrease of crystallite size. As the average crystallite size decreased from 37 nm to 7 nm, the conductivity of the nanofibers increased by more than 20 times. An exceptionally high oxide ion conductivity of 0.023 S cm⁻¹ for the nanofibers was observed at 500 °C, which is more than 900 times higher than that of bulk 10ScSZ.