Observation of amorphous domain pattern in ferroelectric sodium nitrite

It has been found that, when the sample platelets of sodium nitrite are quenched from above T-c to room temperature, strongly anisotropic and amorphous domain patterns appear in addition to the well known stripe pattern. A computer simulation shows that both patterns can be formed from the initial lamellar domain structure through the nucleation and growth of antistripples. The amorphous domain patterns appear when the nucleation rate is high and the growth velocity is low. We infer that the quenching provides such a condition to the thin lamellar domains when the temperature of the sample is rapidly cooled in the process of domain pattern evolution.