Modification of the nonlinear optical, dielectric, and structural properties of p-nitroaniline and 2-methyl-4-nitroaniline crystals through recrystallization under a strong dc electric field

Crystals of para-nitroaniline were grown from solution while subjected to a strong dc electric field of 2 X 105 V/m. This resulted in a modification of the unit cell lattice parameters and space group with respect to crystal grown in the absence of an electric field. The modified crystal are capable of generating a second harmonic signal and poses a significantly lower dielectric permittivity.