Growth and properties of sodium tetraborate decahydrate single crystals

Sodium tetraborate decahydrate (Na2B4O7·10H2O) single crystals were grown from aqueous solution by slow solvent evaporation method and its functional groups have been confirmed by FTIR. Grown crystals were found to be hard in nature (n = 1.8). From optical studies band gap of the material was found to be 4.1 eV and PL emission peak was found at 340 nm which can be due to annihilation self trapped excitons present in borate crystals. Dielectric constant was found to increase with temperature up to 70 °C. Conductivity obeys Jonscherʹs power law as seen at different temperatures. Activation energy of the crystal was found to be 2.05 eV.