Single crystal structure and SHG of defect pyrochlores CsBVMoO6 (BV=Nb,Ta)

•CsNbMoO6 and CsTaMoO6 homogeneous single crystals have been grown.•The crystal structure of CsTaMoO6 has been studied.•Nonlinear optical properties of CsNbMoO6 and CsTaMoO6 have been found.•The microscopic origin of the second harmonic generation (SHG) response have been identified.

The crystal structure and non-linear optical properties of CsNbMoO6 and CsTaMoO6 defect pyrochlores have been studied. The single crystals of these compounds grown by the flux method possess an octahedral faceting and reach up to 50 µm in size. The crystal structures of CsBVMoO6 (BV=Nb, Ta) were investigated by X-ray diffraction method. Both compounds crystallize in the cubic symmetry with noncentrosymmetric space group F-43m. The second harmonic generation of CsNbMoO6 and CsTaMoO6was found to be 1.6×10−2 and 8.5×10−4 of lithium niobate, correspondingly. It has been determined that distortions of [MO6] polyhedra (M=Nb, Ta, Mo) as well as polarizability and covalency of Nb–O and Ta–O bonds have a great effect on the second harmonic generation.

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