α-MoO₃ Nanosheets Prepared Using a Dynamic Magnetic Field for In-Plane Anisotropic Optics

The dynamic magnetic field was harnessed for the quick growth of the MoO3 nanosheet. We set a magnetic channel by coupling the dynamic magnetic fields with nonmagnetic molecules for realizing a quick and stable transport and collection of gas molecules, instead of the diffusion way. Motivated mainly by the forces arising from the dynamic magnetic field, the quality α-MoO3 nanosheets are aligned along the direction of the magnetic fields, where their growth speed can reach as high as 2–3 orders of magnitude compared to the diffusion driven by concentration gradients alone. The final obtained α-MoO3 nanosheets exhibit good crystalline properties and ultrathin thickness along the (010) orientation. Angle-resolved polarization Raman spectroscopy confirms that α-MoO3 nanosheets have strong Raman anisotropy, where the Ag mode can be used to identify the crystal orientation of α-MoO3. Our findings can be adopted as a highly efficient method to prepare nanosheets of high-quality two-dimensional materials.