Thermophysical, mechanical and dielectric studies on piperidinium p-hydroxybenzoate A novel organic NLO single crystal

Single crystals of recently identified nonlinear optical material, piperidinium p-hydroxybenzoate (PDPHB), were grown by solution cooling method. It crystallizes in a monoclinic system with a noncentrosymmetric space group Cc. Thermal stability and decomposition behavior of PDPHB are illustrated through thermogravimetric, differential thermal and differential calorimetric analysis. The thermal diffusivity, thermal conductivity, and specific heat capacity of the grown crystals, which are the three most important thermo-physical parameters in heat transfer calculations, are calculated by an improved photopyroelectric technique. The room temperature hardness test has been performed on crystallographic planes (200), (020), and (002) using Vickers microhardness tester and the results are analyzed through the classical Meyer's law. The dielectric constant, dielectric loss, and ac conductivity are studied as a function of frequency (100 Hz to 1 MHz) and temperature (313-363 K). All these studies are performed for the first time and aimed to explore the useful and safe region of thermal, mechanical, and electrical properties to enhance effectiveness of PDPHB crystals for device fabrications.