Ferroelectric Glycine Phosphite (GPI) crystal have been grown from aqueous solution employing the slow cooling technique. As the crystal solubility in water depends on temperature, single crystals were grown. Transparent, colourless crystals with habit morphology weighing about 8g were obtained with in a month. The same procedure was used to grow single crystals of 10 wt% of Thiourea doped GPI (TUGPI). Formation of a new crystal was confirmed by Powder X-ray diffraction studies as well as FTIR studies. Crystalline quality were found using rocking curve for both the crystals. Due to the presence of Thiourea in TUGPI, it improves the crystalline perfection and also enhances the growth rate. The variation of hardness on (010) faces of monoclinic GPI and TUGPI crystals, with load were studied .Vickers hardness numbers, H v were found to decrease with the increase in load. The value of Mayer's index 'n' was found to be greater than 1.6 for GPI and TUGPI showing soft-material category. The results are discussed in detail.

], abbreviated as GPI is the second hydrogen bonded ferroelectric crystal combination of phosphorous acid and amino acid following betanine phosphite crystals abbreviated as BPI. Sankaranarayanan and Ramasamy-Technique was adopted to prepare the ferroelectric glycine phosphite unidirectional single crystal. The growth orientation was imposed by the pre-grown <010> seed. As water was the solvent, transparent, colourless crystal with cylindrical shaped ingot of sized 20mm-diameter was grown. Powder X-ray diffraction, HRXRD, FTIR, dielectric and mechanical studies were carried out. The results are discussed in detail.