Studies on growth and properties of pure and doped metals rare earths dyes and amino acid Glycine Phosphite GPI single crystals

Abstract

Ferroelectricity in Glycine Phosphite abbreviated as GPI was first observed in the year 1996. GPI is obtained from the combination of amino acid (Glycine) and inorganic acid (Phosphorous acid). GPI and deuterated GPI undergo a continuous ferroelectric phase transition at 224 K and 324 K respectively. Growth and characterization of pure and doped Glycine Phosphite single crystals were carried out. GPI was obtained from glycine and phosphorous acid in equi molar ratio. Various supersaturation ratio were adopted in the temperature lowering methods to optimize the growth, lower the cooling rate improve the quality of crystals but takes longer growth duration. Single crystal X-ray diffraction studies were carried out to determine the lattice parameters and to understand structural morphologies for pure and doped GPI crystals. HRXRD studies were used to determine the crystalline perfection, structural, optical quality of single crystals and reveal some interesting features on the effect of incorporation of the different dopants in the crystalline matrix. Crystalline phases of pure and GPI crystals were identified by powder X-ray diffraction methods. Variation of transparency and cut-off wavelengths of pure and doped crystals were analyzed and compared with pure GPI material. DSC measurements were carried out in the low temperature region (200 K 300 K) for identifying the paraelectric to ferroelectric transition temperature which shows the significant shift of Tc towards the higher temperature in the case of few metals and amino acid doped GPI crystals compared to pure. The single crystals of pure and doped GPI were grown from solvent evaporation and temperature lowering methods. Grown crystals were characterized with various characterization techniques. Among the dopants few metals and amino acid dopants enhance the structural, optical, thermal, dielectric, piezoelectric, ferroelectric and mechanical properties significantly. However other dopants show slight improvement of all properties. newline newline newline