Enhanced ferroelectric properties and crystal structure of TGS_0.74P_0.26 single crystals

The single crystals of triglycine sulpho phosphate (TGS_0.74P_0.26) were grown by slow evaporation method with 0.6 M of phosphoric acid in the growth solution. The crystal structure of the grown crystal is refined with 0.74 sulphur and 0.26 phosphorous occupancy with the formula of TGS_0.74P_0.26 using single crystal x-ray diffraction analysis. The dielectric, ferroelectric and pyroelectric properties of the TGS_0.74P_0.26 single crystals were investigated. The coercive field (E_c) and internal bias field (I_b) values are 8 kV/cm and 1.4 kV/cm, respectively and these values are found increased compared to the pure TGS and also low dielectric loss was observed. The pyroelectric coefficient of TGS_0.74P_0.26 crystal is 0.023 µC/cm²/°C and the pyroelectric figure of merit for current, voltage and detectivity are F_i = 105 pm/V, F_v = 0.055 m²/C and F_d = 22 µPa^−1/2 respectively. Enhanced ferroelectric properties were observed when compared to the pure TGS crystals. The figure of merit for the detectivity (F_d) shows higher values when compared with that of the well-known materials such as PZT (11.5 µPa^−1/2) and other lead free materials such as SBN (7.21 µPa^−1/2) and CSBN (12 µPa^−1/2). With these excellent properties, the TGS_0.74P_0.26 single crystal can be a promising material for the pyroelectric detector applications.