Nano-ionic thin films of gadolinia-doped ceria prepared by pulsed laser ablation

Abstract

Microstructural properties of nano-ionic thin films of gadolinia-doped ceria (GDC) prepared by pulsed laser ablation from sintered targets of gadolinia (5-20 mol%) doped ceria are investigated. The ionic conductivity measurements of the sintered pellets showed a decrease in the activation energy from 1.1 to 0.65 eV for 5 and 30 mol% gadolinia-doped ceria, respectively. The microstructural properties of the GDC films as a function of substrate temperature, oxygen partial pressure, and laser energy show that the films are polycrystalline in the entire range of substrate temperature. The grain size is found to increase with increasing temperature up to 873 K. Further improved crystallinity is noticed for the films grown with oxygen partial pressure of 0.1-0.2 mbar. X-ray diffraction and transmission electron microscopy (TEM) reveal nanocrystalline grains with textured growth along <111> orientation in these films at low substrate temperature and at lower oxygen partial pressure. TEM study shows a uniform distribution of nanocrystal of 8-10 nm for energies ≤200 mJ/pulse, and nanocrystals embedded in a large crystalline matrix of doped ceria for energies in the range 400-600 mJ/pulse. Raman spectroscopy also confirms the defects in these films. The study also reveals that the substrate temperature and oxygen partial pressure could influence preferred orientation, while the laser energy could significantly influence defect concentration in these films.

Effect of oxygen partial pressure on the microstructural, optical and gas sensing characterization of nanostructured Gd doped ceria thin films deposited by pulsed laser deposition

“…The spectra of the thin films have shown (1 1 1), (2 0 0), (2 2 0) and 3 1 1reflections. Due to increase in oxygen partial pressure the film orientation is found to alter from (1 1 1) to (2 0 0) plane in the partial pressure range 50-200 mTorr [24]. The intensity of the peak corresponding to (2 0 0) reflection is found to increase with an increase in oxygen partial pressure.…”

“…Many research articles in the literature are reported as the preparation of doped ceria thin films by chemical or physical methods such as spray pyrolysis [16], atomic layer deposition [17], sol-gel spin coating [18], dip-coating [19], metalorganic deposition [20], pulsed laser deposition [21]. Among these numerous deposition techniques, the pulsed laser deposition method is an unique and simple technique that can be used to prepare extremely good quality films from a wide variety of materials and compounds.…”

Electrical Conductivity of NiO-Gadolinia Doped Ceria Anode Material for Intermediate Temperature Solid Oxide Fuel Cells

“…The enhanced conductivity is attributed due to the formation of oxygen defect (V o ‫)״‬ in the ceria lattice by the introduction of aliovalent dopants [34]. Among the various trivalent dopants, Gd 3+ ion has found increased ionic conductivity at doping level of 5-30 mol% with ceria [35][36][37][38][39]. Therefore the combination of NiO-GDC composite would serve the purpose of fabrication of anode or anode precursor material for IT-SOFC.…”

Synthesis and Characterization of Nanosized Dy-Doped of Ceria Developed by Microwave Assisted Combustion Route

“…3 .6H 2 O) were mixed initially in a quartz beaker. Glycine nitrate was added to the mixed metal nitrate solution.…”

“…In the last decade, nanocrystalline materials have been widely accepted to have a high potential to overcome these constraints. Nano-ionic ceramic oxides are displaying electrical properties which appear to be unique and may lead to applications that are not attainable by conventional microcrystalline oxides [3]. The ionic conductivity has been found significantly enhanced in nanocrystalline materials compared to the microcrystalline ones [4].…”