Magnetic Measurements to Identify Ion Valency and Position in Doped and Mixed Oxides

Doped and mixed oxides are a class of materials with widespread applications, ranging from electronics to energy storage. The precise determination of ion valency in these materials is crucial for understanding their electronic, ionic, magnetic, and other properties, as well as controlling behaviors during processing and microstructure development. In this review, we present magnetometry measurement as a powerful tool to determine ion valency and position in doped and mixed oxides. Focus is given to transition metals in dilute concentrations. We discuss the theoretical framework, experimental techniques, data analysis methods, and case studies that showcase the effectiveness of magnetometry in elucidating the valency of ions in various oxide systems. The results highlight the importance of magnetometry as a nondestructive and highly sensitive technique for characterizing the valence states and positions of dopant ions. They position magnetometry as a valuable member of the suite of complementary advanced tools for characterizing ion valency.