Top-seeded solution growth and characterization of Raman crystal LiVMoO6

Abstract

Single crystal LiVMoO₆, with dimensions up to 20 mm × 15 mm × 12 mm, has been grown successfully for the first time from a high-temperature solution with MoO₃ as a flux. LiVMoO₆ crystalizes in the monoclinic system with space group C2/m (no. 12) and unit cell parameters of a = 9.3531(9) Å, b = 3.6477(4) Å, c = 6.647(4) Å, β = 111.643° and Z = 2. The crystal structure consists of MO₆ (M = Mo and V) and LiO₆ octahedrons mutually combined via corner sharing to form a 3D network. The as-grown LiVMoO₆ crystal has well-developed faces with major forms {1−11}, {−1−11}, {001}, {100}, {11−1}, and {−11−1}. The crystal exhibits good transmittance from 490 to 4950 nm. High-resolution X-ray diffraction (HRXRD) shows that the full-width at half-maximum (fwhm) of the rocking curve is 47.22′′, indicating high crystal quality. The refractive index coordinate is established using a polarizing microscope. Spontaneous Raman spectra along the Z-axis with different configurations exhibit strong Raman shifts at 963.7 cm⁻¹ and 830.5 cm⁻¹, which are comparable to those of crystalline YVO₄. The results indicate that LiVMoO₆ should be an excellent Raman crystal.