Electrostatic extension of magnetic proximity effect in La0.7Sr0.3MnO3

Magnetic proximity effects are typically limited to a few nanometers due to the short-range nature of the underlying magnetic interactions. Here, we use off-axis electron holography to reveal an electrostatically induced long-range magnetic proximity effect that extends over a distance of 40 nm at a ferromagnetic/paramagnetic interface in ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$. We show that this behavior results from carrier diffusion and drift across the interface, which changes the ${\mathrm{Mn}}^{3+}/{\mathrm{Mn}}^{4+}$ ratio and hence the local Curie temperature and density of magnetic moments.