Crystal growth, optical and luminescence properties of Na ₆ Mo ₁₁ O ₃₆ single crystal

The inorganic material Na ₆ Mo ₁₁ O ₃₆ was synthesized by solid-state reaction, and a single crystal of the compound was grown using the Czochralski technique. The crystal structure of the compound was confirmed by X-ray diffraction (XRD) analysis. The luminescence light yield and fluorescence decay time of the crystal were studied in a temperature range from room temperature to 10 K using a 280 nm light emitting diode (LED) source. The Na ₆ Mo ₁₁ O ₃₆ crystal has no luminescence at room temperature, however, the luminescence intensity is enhanced at low temperatures. Transmittance spectrum measurement was performed to study the optical quality of the crystal. The luminescence light yield of the Na ₆ Mo ₁₁ O ₃₆ was compared with that of a Li ₂ MoO ₄ crystal at different low temperatures. Because of the possibility of growing a single crystal of Na ₆ Mo ₁₁ O ₃₆ , which has a significant luminescence light yield at 10 K and no heavy elements, this crystal can be a good candidate for a rare event search experiment searching for neutrinoless double beta (0νββ) decay at cryogenic temperatures.