Revisiting KAI theory and its application to mixed composite system “Na(1−x)CsxNO2–PVA” fabricated at moderate elevated temperature

AbstractIshibashi and Takagi considered ‘ferroelectric domain switching’ just equivalent to ‘phase evolution during crystal growth’. They slightly modified Kolmogorov and Avrami’s classical theory of ‘phase transformations in crystal growth’ and applied it to the switching data in ferroelectrics. Here an effort is made to elucidate mathematical steps in evolution of this new KAI model used to fit experimental switching data to estimate microscopic switching parameters. In mixed composite system Na(1−x)CsxNO2−PVA (x = 0.09), the domain growth dimension (d) is found to expand from 0.1587 to 0.3445 when signal amplitude changed from 10V to 15V. The cesium substitution is supposed to have enabled lone pairs on central nitrogen of nitrite group to orient constituting N−O branches into more ordered state in the matrix of molecular chains of the PVA facilitating control of crystallization process which led to lowering of strain giving rise to the increased change in Imax with change in pulse amplitude.