Interisland-Distance-Mediated Growth of Centimeter-Scale Two-Dimensional Magnetic Fe<sub>3</sub>O<sub>4</sub> Arrays with Unidirectional Domain Orientations
Peng Wang, Jun Ge, Jiawei Luo, Hao Wang, Luying Song, Zhongwei Li, Junbo Yang, Yuzhu Wang, Ruofan Du, Wang Feng, Jian Wang, Jun He, Jianping Shi
Abstract
Two-dimensional (2D) nanosheet arrays with unidirectional orientations are of great significance for synthesizing wafer-scale single crystals. Although great efforts have been devoted, the growth of atomically thin magnetic nanosheet arrays and single crystals is still unaddressed. Here we design an interisland-distance-mediated chemical vapor deposition strategy to synthesize centimeter-scale atomically thin Fe 3 O 4 arrays with unidirectional orientations on mica. The unidirectional alignment of nearly all the Fe 3 O 4 nanosheets is driven by a dual-coupling-guided growth mechanism. The Fe 3 O 4 /mica interlayer interaction induces two preferred antiparallel orientations, whereas the interisland interaction of Fe 3 O 4 breaks the energy degeneracy of antiparallel orientations. The room-temperature long-range ferrimagnetic order and thickness-tunable magnetic domain evolution are uncovered in atomically thin Fe 3 O 4 . This strategy to tune the orientations of nanosheets through the an interisland interaction can guide the synthesis of other 2D transition-metal oxides, thereby laying a solid foundation for future spintronic device applications at the integration level.