Synthesis, growth and characterization of strontium manganese hydrogen phosphate (SrMnHPO4) single crystal for NLO applications

High quality and optical transparency single crystal of strontium manganese hydrogen phosphate (SrMnHPO4) are grown in silica gel medium using concentrations of ortho- phosphoric acid and supernatant solutions in single diffusion process. The gel pH plays an important role in the formation of SrMnHP crystals. The grown crystal was characterized by TG–DTA, XRD, FTIR, UV, PL, Dielectric, AC conductivity and SHG test. The TGA and XRD results suggest that the SrMnHP single crystal was triclinic crystalline structure. Inductively coupled plasma mass spectrometry (ICP–MS) results illustrate that the 2.5 mol% and 5 mol% of Sr and Mn ion present in HPO4 compound. Transmittance spectrum reveals that the crystal has a low UV cut-off of 360–510 nm and has a good transmittance in the entire visible region and the calculated band gap of 2.58 eV. The PL studies indicate that the grown crystals have a blue and green fluorescence emission. The SrMnHPO4 show significant improvement in the dielectric and AC conductivity of the grown crystals. The AC activation energy of the grown crystal was found to be 0.201 eV, demonstrating that SrMnHPO4 bulk crystal has high activation energy. SrMnHPO4 had a SHG efficiency of (36), which is 4.8 times better than of KDP single crystal (7.5). The grown crystals were also characterized by SEM, TEM and etching studies. The optimum results are reported and discussed in detailed manner.