Highly enhanced electrical conductivity in electrospun La9.6Si6O26.4 nanofibres

Oxy-apatite La_9.6Si₆O_26.4 nanofibres have been prepared by electrospinning from a sol-gel precursor solution and following calcination. The morphologies and phases of nanofibres were characterised by scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction. The results showed that when the precursor nanofibres were calcined in ambient air, oxy-apatite structured La_9.6Si₆O_26.4 was formed over the 750-900-C temperature range without any impurities. Moreover, the temperature-dependent electrical properties of La_9.6Si₆O_26.4 nanofibres were tested by AC impedance spectra, showing an electrical conductivity of 1.5×10^-2 S/cm at 600 C in air. According to the electrical tests and microstructure analysis, it was proposed that the enhanced electrical conductivity in La_9.6Si₆O_26.4 nanofibres is mainly attributed to the oxygen-ion conduction on the surface and their nano-sized grains.