Optical, dielectric and microhardness studies on 1 0 0 directed ADP crystal

1 0 0 directed ammonium dihydrogen phosphate single crystal has been grown using the uniaxially solution-crystallization method of Sankaranarayanan–Ramasamy (SR). The size of the grown crystal is 40 mm in diameter and 50 mm in thickness. The grown crystals were characterized by UV–vis spectroscopy, Vickers hardness and dielectric studies. Comparing the 1 0 0 plane of the conventional method grown ADP crystal with 1 0 0 directed SR method grown ADP crystal, optical transparency, dielectric constant and Vickers hardness number are increased and dielectric loss is decreased in SR method grown crystal.