Domain Walls at Rest
This chapter is devoted to the properties of domain walls and let us stress first that here we have in mind a static situation in a ferroic sample. Problems connected with domain walls which are not in static or quasistatic equilibrium will be dealt with separately in Chap. 8. An important aspect of walls has been already discussed in Chap. 2, namely their orientation from the point of view of electrical and mechanical compatibilities of neighboring domains. There we considered walls as infinitely thin two-dimensional objects. Now we focus on its internal structure and properties governed by this structure. In Chap. 4 we have pointed out that several domain-imaging methods provided information about the wall thickness; in Sect. 6.1 we wish to describe some of these observations in more detail. In this section, we will also present available experimental data on thickness and surface tension of domain walls.