Mass-Mediated Phase Modulation of Thin Molybdenum Nitride Crystals on a Liquid Cu-Mo Alloy.

The high-quality and controllable preparation of molybdenum nitrides (Mo_xN_y) will significantly advance the fields of heterogeneous catalysis, energy storage, and superconductivity. However, the complex structure of Mo_xN_y, which contains multiple phases, makes exploring the structure-property relationship challenging. The selective preparation of Mo_xN_y with distinct phases is undoubtedly an effective method for addressing this issue, but it is lacking experimental cases and theoretical reports. Here we demonstrate a feasible chemical vapor deposition (CVD) strategy for selectively producing γ-Mo₂N or δ-MoN through modulating the mass quantity of N precursors. A liquid Cu-Mo alloy was used as a Mo precursor and catalyst in this system. The resulting γ-Mo₂N was systematically characterized and found to be of high quality. Furthermore, the morphology evolutions of γ-Mo₂N and δ-MoN with growth time were summarized in detail, as a result of growth and etching dynamics. This work promotes the phase modulation of Mo_xN_y and provides a framework for future research on the structure-property relationship. [ABSTRACT FROM AUTHOR]