Dielectric and pyroelectric properties of TGS crystals doped with nitroaniline molecules

TGS crystals grown isothermally in ferroelectric phase were doped with ortho- meta- and para-nitroaniline molecules with dipole moments from 4 up to 6 D. From 100 to 350 K, the dielectric and pyroelectric properties of pure and nitroaniline-doped TGS crystals were measured and the results obtained were compared. The dielectric permittivity of TGS crystals doped with nitroaniline molecules compared with pure TGS crystals was found to decrease with increasing magnitude of the dipole moments of the nitroaniline molecules. On the other hand, the spontaneous polarization and pyroelectric coefficient of TGS crystals doped with nitroaniline molecules increase with increasing dipole moments of the nitroaniline molecules. The highest values of spontaneous polarization and pyroelectric coefficient in comparison to pure TGS crystals were found for crystals doped with para-nitroaniline molecules of dipole moment 6 D. At room temperature these values are by about 30 percent higher than in pure TGS crystals.