The Growth and Properties of Guanylurea Hydrogen Phosphite Crystal

Aqueous solutions of guanylurea hydrogen phosphite (GUHP) have been synthesized. The temperature dependence of equilibrium GUHP concentration in water was obtained. The change in the density of aqueous GUHP solutions with a change in their concentration was investigated. The influence of the solution pH on the GUHP solubility in water in the temperature range of +25–45°C was analyzed. The crystallization range of monoclinic GUHP crystals, belonging to the sp. gr. Cc, was determined. GUHP crystals were grown using different methods, based on cooling or maintaining a constant temperature, with mixing aqueous solutions or without mixing. The properties of the grown crystals in the optical and THz ranges were investigated.