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采用反应磁控溅射方法,在(0001)蓝宝石单晶衬底上,制备了纳米多晶Gd2O3掺杂CeO2(GDC)氧离子导体电解质薄膜,采用X射线衍射仪(XRD)、原子力显微镜(AFM)对薄膜物相、结构、粗糙度、表面形貌等生长特性进行了表征,利用交流阻抗谱仪测试了GDC薄膜不同温度下的电学性能;实验结果表明,GDC薄膜为面心立方结构,在所研究的衬底温度范围内,均呈强(111)织构生长;薄膜表面形貌随衬底温度发生阶段性变化:衬底温度由室温升高到300℃时,对应球形生长岛到棱形生长岛的转变,当完全为棱形岛生长时(300℃),生长岛尺寸显著增大;从400℃开始,则发生棱形生长岛到密集球形生长岛的转变,球形生长岛尺寸明显减小.生长形貌的转变反映着薄膜生长初期不同的成核机理,很可能与蓝宝石(0001)面的表面结构随温度变化有关;GDC多晶电解质薄膜的复平面交流阻抗谱主要源于晶界的贡献,根据Arrhenius图求得电导活化能Ea在1.2—1.5eV范围内,接近于晶界电导的活化能值,并且随衬底温度升高Ea减小(Ea300>Ea400>Ea600);电导活化能以及晶粒尺寸不同,导致GDC薄膜电导率随测试温度的变化规律不同.
Nanocrystalline Gd2O3 doped CeO2 (GDC) oxide ion conductor electrolyte films were prepared on (0001) sapphire single crystal substrate by reactive magnetron sputtering. The films were characterized by X-ray diffraction (XRD), atomic force microscopy ) Were used to characterize the growth characteristics of the films, such as structure, roughness, surface topography and so on. The electrical properties of GDC films at different temperatures were tested by AC impedance spectroscopy. The experimental results show that the GDC films are face-centered cubic structures. The results show that the surface morphology of the films changes stepwise with the substrate temperature when the substrate temperature is raised from room temperature to 300 ℃, corresponding to the spherical growth island The change of prismatic growth island, when fully grown into a prismatic island (300 ℃), the size of the growing island increased significantly; from 400 ℃, the transition from prismatic growth island to intensive spherical growth island occurred, and the size of the spherical growth island And the change of the growth morphology reflects the different nucleation mechanism at the initial stage of film growth, which is probably related to the change of the surface structure of the sapphire (0001) surface with temperature. The complex plane AC impedance spectrum of the GDC polyelectrolyte film is mainly derived from The contribution of grain boundaries, according to Arrhenius graph, the activation energy Ea is in the range of 1.2-1.5eV, which is close to the activation energy of the grain boundary conductivity, and decreases with increasing substrate temperature (Ea300> Ea400> Ea600); the conductance activation energy and the grain Different size, resulting in GDC film conductivity with the test temperature changes in different laws.