Fig. 4: Schematics revealing mechanisms for the different trends of the ferroelectric polarization across the type I and II DWs.
From: Ferroelectric polarization and magnetic structure at domain walls in a multiferroic film
a Type I DW. b Type II DW. The spontaneous polarization of (FeAFeD)O6 layers is 8 times as that of (FeBFeC)O6 layers, which results in the bound charges of ±7q between the (FeBFeC)O6 and (FeAFeD)O6 layers. The bound charges of −2q and −8q are induced at the type I and type II DWs, respectively. The decrease of negative bound charges at the type I DW will induce a local electric field (Red arrows) pointing away from the DW in a, which will enhance the polarization. In contrast, a local electric field (Red arrows) pointing to the DW is formed due to the increase of negative bound charges at the type II DW in b, which will reduce the polarization.
