Low-temperature synthesis of AMoO₄ (A = Ca, Sr, Ba) scheelite nanocrystals

An extension of the vapor diffusion sol-gel method to the synthesis of the AMoO₄ (A = Ca, Sr, Ba) scheelite family of materials is reported. Sub-30 nm quasispherical nanocrystals were obtained after vapor diffusion at room temperature, followed by thermal aging at 80 C. Rietveld analysis of X-ray diffraction data, Raman spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy demonstrated that the vapor diffusion sol-gel method affords crystalline and phase-pure AMoO₄ nanocrystals with excellent compositional control. The potential lithium storage capacity of the CaMoO₄ nanocrystals versus Li at a rate of C/4 was also investigated. The nanocrystals exhibited an extremely large first discharge capacity of 1300 mA h g^-1, which stabilized at 250 mA h g ^-1 after 25 cycles.