Crystal growth and optical properties of ammonium dihydrogen phosphate (ADP) crystals doped with Fe(II) and Fe(III): Oxidation number effects

Single crystals of Fe(II) and Fe(III) (1 mol %) doped ammonium dihydrogen phosphate crystals were obtained by slow evaporation solution growth technique (SEST). Single crystal X-ray diffraction studies of doped samples shows slight structural changes. The obtained crystals was further characterized by FT-IR, SEM, UV-DRS. The band gap energies of the crystals were estimated by the application of Kubelka-Munk algorithm. Second harmonic generation (SHG) efficiency of Fe(II) and Fe(III) crystals let out that Fe(II) doping in ADP has better nonlinear optical (NLO) property than Fe(III) due to lattice stress.