Tuning the magnetism of epitaxial cobalt oxide thin films by electron beam irradiation

Tuning the magnetic properties of perovskite thin films is of great significance for the design of future devices using related materials. The magnetization of LaCoO${}_{3}$ thin films is closely related with the stripelike superstructures observed in the atomic-scale images. In this work, the authors show that the magnetization of La${}_{0.9}$Ca${}_{0.1}$CoO${}_{3}$ thin films grown on SrTiO${}_{3}$ substrate decreases with the substitution of La${}^{3+}$ ions by Ca${}^{2+}$ ions. Interestingly, the magnetization could again increase by introducing the stripelike superstructures in a continuous and controllable manner using electron beam irradiation. These findings not only pave the way for tuning the magnetization of La${}_{0.9}$Ca${}_{0.1}$CoO${}_{3}$ thin films artificially by electron beam irradiation, but also help to deeply understand the origins of the magnetism of La${}_{0.9}$Ca${}_{0.1}$CoO${}_{3}$ thin films.