Singular magnetic properties of porous anodized tin oxide ceramics

Porous SnO2 films were successfully prepared using pure tin foils by a convenient electrochemical anodization method in 0.5 M NaOH solutions. Interestingly, the same sample can simultaneously exhibit room temperature ferromagnetism, paramagnetism and diamagnetism. Moreover, the magnetic behavior is related to the direction of the applying magnetic field, showing obvious magnetic anisotropy. A reasonable explanation for this phenomenon was given by analyzing the morphology, magnetic characterization, and spectral analysis of the films, combined with the knowledge of solid physics. This research will be helpful in expanding the application of porous SnO2 films.