Na2Te3Mo3O16:  A New Molybdenum Tellurite with Second-Harmonic Generating and Pyroelectric Properties

The synthesis, structure, and characterization of a new noncentrosymmetric molybdenum tellurite, Na2Te3Mo3O16, are reported. Na2Te3Mo3O16 crystallizes in the noncentrosymmetric monoclinic space group I2 (No. 5, cell choice 3) with a = 7.3373(10) Å, b = 11.2668(16) Å, c = 8.2369(18) Å, and β = 97.387(3)°. The material exhibits a quasi-one-dimensional crystal structure, with each chain consisting of edge-shared MoO6 octahedra that are connected by TeO3 and TeO4 polyhedra. The SHG efficiency of Na2Te3Mo3O16, using 1064 nm radiation, is approximately 500 × α-SiO2 and is phase-matchable (type 1). The strong SHG efficiency is maintained up to the melting temperature. The maximum polarization is 0.189 μC/cm2 at 25 kV/cm, and the pyroelectric coefficient (total effect), p, is −2.6 μC/m2 K.