Enhanced Magnetism in Cation‐Modulated Manganite Heterostructures

ABSTRACT Transition metal oxides exhibit a variety of physical properties that are tuned by external stimuli such as electric and magnetic fields, mechanical stress, and the formation of heterointerfaces. Oxide superlattices provide a useful system for amplifying the interfacial effects. These effects often become more pronounced with decreasing thickness of the individual layer and increasing number of interfaces. In this study, we investigated the changes in the magnetic properties of cation‐modulated manganite superlattices fabricated from a single manganite target by varying the oxygen partial pressure, resulting in the modulation of cation stoichiometry. Using superconducting quantum interference device (SQUID) magnetometry, we found that the magnetization in superlattices of cation‐modulated manganites increased by up to 36.8 ± 0.4% relative to the volume‐weighted average of the corresponding single‐layer films. Polarized neutron reflectometry further revealed a larger average magnetic response in the shorter‐period superlattice, consistent with the trend observed by SQUID magnetometry. This observation is consistent with the interface‐related magnetic interactions between the layers. These findings point to an interface‐driven route to enhance magnetization in cation‐modulated manganite superlattices and show that the effect is tunable by altering the number of interfaces.