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A prominent laser crystal Nd 3+ :NaLu(MoO 4 ) 2 with dimension of 25 × 20 × 8 mm 3 was successfully grown from a flux of Na 2 Mo 2 O 7 by the mean of top-seeded solution growth technique. The crystal phase was confirmed by the XRD powder diffraction. The results of the DSC measurements indicate that the melting point of this crystal is 1060 ± 5 °C and that the crystal will decompose into the compounds of Na 2 MoO 4 and Lu 2 (MoO 4 ) 3 when the temperature is above its melting point. The hardness of the crystal is about 440 VDH. The crystal has broad absorption and emission cross-sections. The largest absorption cross-sections are 11.48 × 10 −20 cm 2 and 4.05 × 10 −20 cm 2 at about 817 nm for the π- and σ-polarizations with the full width at half-maximum (FWHM) of 10 nm and 16 nm, respectively. The emission cross-sections reach to 12.31 × 10 −20 cm 2 at 1064 nm for the π-polarization and 6.22 × 10 −20 cm 2 at 1069 nm for the σ-polarization. The lifetime is estimated to be 127.6 μs. The laser experiment has also been performed and the highest slope efficiency is about 30.6%. All the results demonstrate that Nd 3+ :NaLu(MoO 4 ) 2 crystal may be a potential laser gain medium for the diode laser pumping. [ABSTRACT FROM AUTHOR]

An Nd 3+ :KBaY(MoO 4 ) 3 crystal with dimensions of 27 × 21 × 8 mm 3 was grown by the TSSG method. KBaY(MoO 4 ) 3 crystal with disordered structure crystallizes in the monoclinic system with space group C2/c. The spectral properties of KBaY(MoO 4 ) 3 crystal have been investigated. It exhibits broad absorption and emission bands, which is caused by its disordered structure and distorted Y(Nd) O 8 polyhedron. Nd 3+ :KBaY(MoO 4 ) 3 crystal has large values of peak absorption and emission cross-sections. The fluorescence quantum efficiency η is up to 97.3%. Therefore, the combination of all the optical parameters favorably distinguishes the Nd 3+ :KBaY(MoO 4 ) 3 crystal from other Nd-doped crystals and makes it as a promising laser material for DPSSL application. [ABSTRACT FROM AUTHOR]

In this paper, four NiO nano-arrays with different morphology on nickel foam were synthesized by a hydrothermal approach. It is found that the porous single crystal NiO nanoflake array (PNFA) holds superior electrochemical properties, better than the other three samples. The specific capacitance of the PNFA obtained from the cyclic voltammetry curve was 716 F g−1 and that derived from the galvanostatic charge-discharge curve was 589 F g−1 in three-electrode system. The cycling stability of the PNFA could retain as high as 92.4% after 5000 cycles. When the PNFA was assembled into a symmetric supercapacitor, the PNFA//PNFA device exhibited an energy density of 39.3 W h kg−1 (at 550 W kg−1) and could retain 13.2 W h kg−1 (at 11,000 W kg−1) in two-electrode system. Furthermore, the SEM, XRD, TEM and XPS results prove that the PNFA is a special porous single crystal structure, which combines the advantages of the cross-linked single crystal structure for facilitating electron transfer and the porous structure providing more interfaces for insertion/exit of electrolyte ions from the active material. It indicates that the PNFA is a potential electrode material for supercapacitors. [Display omitted] • Porous single crystal NiO nanoflake array (PNFA) is directly grown on nickel foam. • The PNFA is prepared by a facile hydrothermal method following an annealing process. • The PNFA combines the advantages of porous material and single crystal material. • The PNFA shows a specific capacitance of 716 F g−1 at a scan rate of 5 mV/s. • The PNFA//PNFA supercapacitor has an energy density of 39.3 W h kg−1 at 550 W kg−1. [ABSTRACT FROM AUTHOR]