Oxygen non-stoichiometry profoundly impacts the electrical, magnetic, and catalytic properties of metal oxide. Limited by the low mass and volume of thin oxide films, conventional quantification methods, such as thermogravimetry, are not directly applicable. While chemical capacitance has been successfully applied to monitor oxygen non-stoichiometry in thin oxide films, detailed a-priori understanding of the defect chemistry is often very helpful in its interpretation. In this study, changes in non-stoichiometry in Pr doped CeO₂ (PCO) thin films are measured by coulometric titration. I-V titration measurements are performed on electrochemical cells, over the temperature range from 550 to 700 ℃, oxygen partial pressure range from 10^-4 to 0.21 atm, and bias range of -50 mV to 50 mV, to extract changes in stoichiometry. The results agree well with values obtained by chemical capacitance, demonstrating the utility in applying coulometric titration to investigate oxygen non-stoichiometry in oxide thin films.

氧非化学计量深刻地影响金属氧化物的电学、磁学和催化性能。受薄氧化膜质量和体积小的限制，传统的量化方法，如热重分析法，不能直接应用。虽然化学电容已成功应用于监测薄氧化物薄膜中的氧非化学计量，但对缺陷化学的详细先验理解通常对其解释非常有帮助。_{在这项研究中，Pr 掺杂的 CeO 2} (PCO) 薄膜中非化学计量的变化是通过库仑滴定法测量的。I - V滴定测量在电化学电池上进行，温度范围为 550 至 700 ℃，氧分压范围为 10 ^-4至 0.21 atm，偏置范围为 -50 mV 至 50 mV，以提取化学计量的变化。结果与通过化学电容获得的值非常吻合，证明了应用库仑滴定法研究氧化物薄膜中氧非化学计量的效用。