Influence of an alkali metal dopant Rb on the structural, mechanical and optical properties of an UV-transparent ammonium pentaborate crystal.

The UV transparent nonlinear optical crystals of undoped and Rb doped ammonium pentaborate tetrahydrate have been grown by slow evaporation technique at 32 °C. Presence of dopants in the crystal lattice is confirmed by energy dispersive X-ray analysis and by the reduced intensity of NH stretching vibrations in the Raman spectrum. Enlargement of the unit cell of Rb doped crystal is in correlation with the size of the dopant.