Preparation And Properties Of The (SrTiO₃/ZrO₂:8 Mol%Y₂O₃/Ce_0.9Gd_0.1O2-?N Superlattice Electrolytes

On the Al2O3 single wafer,SrTiO3(STO)?ZrO2:8 mol%Y2O3(YSZ)and Ce0.9Gd 0.1O2-??(GDC)have been deposited in turn,using the pulsed laser deposition(PLD)method.Keeping the total thickness as constant(300 nm),by adjusting the laser sputtering number to control the thickness of each layer of electrolyte films.Five different(STO/YSZ/GDC)N(N = 1,4,6,10,20)electrolyte films were fabricated.In the first part of the experiment,the effect of substrate temperature(600 ?-750 ?)on the microstructure and electrical properties of the STO/YSZ/GDC electrolyte were studied.750 ? was the optimum substrate temperature.In the second part,the effect of annealing temperature on the crystal structure of the(STO/YSZ/GDC)N electrolyte were studied.800 ? was the optimum annealing temperature.The electrochemical properties of the electrolyte films with different thickness ratios(1:1:1 andl:1:2)were analyzed.The surface and cross-section micro-morphology of the(STO/YSZ/GDC)N electrolyte were studied throuth scanning electron microscopy.With the increase of annealing temperature film surface become uniform,dense.The epitaxial growth of the film is excellent.According to high resolution transmission electron microscopy(TEM)observation,the boundary between electrolyte layers is obvious,no element diffusion phenomenon occurs between the layers,transport properties are excellent.Electrochemical measurements show that the conductivity of the electrolyte film increases with increasing number of layers.At the same temperature,the electrical conductivity of electrolyte film(STO/YSZ/GDC)N is higher than that of single layer YSZ electrolyte film and the GDC/YSZ bilayer electrolyte film.At the same annealing temperature,the superlattice(STO/GDC/YSZ)N electrolyte film(1:1:1)of conductivity is less than that of superlattice(STO/GDC/YSZ)N electrolyte film(1:1:2).The substrate temperature is 750 ?,the annealing temperature is 800 ?,the superlattice(STO/YSZ/GDC)Nelectrolyte(1:1:2)is an ideal solid fuel cell electrolyte.