Glow Discharge Optical Emission Spectroscopy for Chemical Characterization of Complex Oxide Thin Films and Interfaces

ABSTRACT The development of materials with improved performance and stability relies on the analysis of local compositional inhomogeneities, which may occur at various stages from synthesis to application. This type of analysis benefits from rapid methods that provide high lateral and depth resolution, alongside broad elemental sensitivity. The latter is of paramount importance when considering devices such as lithium‐ion batteries and solid oxide cells, whose operating principle depends on the transfer and accumulation of light elements. In this work, we validate glow discharge optical emission spectroscopy (GDOES) as an alternative to state‐of‐the‐art techniques for the chemical analysis of complex oxides. We consider several systems of technological interest for materials used in energy storage and conversion‐related applications, namely highly complex perovskite oxide thin films with formula ABO ₃ (A = La, Sr, and B = Fe, Co, Mn) and single‐phase SrFeO _3‐δ (SFO). Quantitative, depth‐resolved elemental maps of B‐site cations in combinatorial films are generated and benchmarked against state‐of‐the‐art methods. Additionally, an oxygen quantification was achieved on films subjected to different post‐annealing treatments. This work demonstrates the potential of GDOES for fast analysis of complex oxide films and heterostructures, enabling both laterally and nanoscale depth‐resolved elemental analysis, including difficult‐to‐quantify light elements.