Universal Centimeter‐Scale van der Waals Epitaxy of Ultrathin Single‐Crystalline Ferrites Films

Abstract

Abstract 2D magnetic materials offer significant potential for advanced spintronics, but their practical implementation is hindered by fundamental limitations such as low Curie temperatures and the current inability to achieve scalable, large‐area synthesis. Herein, a significant breakthrough in the centimeter‐scale epitaxial growth of ultrathin single‐crystalline magnetic ferrite films, including cobalt ferrite, manganese ferrite, and nickel ferrite is reported. By leveraging symmetry‐matching‐induced energy splitting between antiparallel orientations and developing a precisely engineered nucleation timing strategy to amplify synergistic coupling, unidirectional epitaxial growth with seamless domain coalescence is achieved. Comprehensive macro‐ and micro‐characterizations confirmed the single‐crystalline nature and high quality. Vibrating sample magnetometry measurements reveal robust ferrimagnetism persisting up to 730 K, while magneto‐optical Kerr effect microscopy visualized sharp uniform single‐domain switching behavior. Interestingly, two potential strategies have been explored for heteroepitaxial integration of CFO thin films with engineered substrates. This work establishes a scalable and viable synthesis route for 2D magnetic oxides, marking a pivotal step toward their practical deployment in high‐performance spintronic and quantum devices.