Continuous Neel to Bloch transition as thickness increases: statics and dynamics

This work studies the magnetic behavior of infinitely long ferromagnetic strips. Two different kinds of domain walls parallel to the long direction can occur in this system: Neel domain wall and Bloch domain wall. In very thin strips the Neel domain wall is energetically favorable. However, as the strips thickness increases, the energy of the Neel wall rapidly grows and at some critical thickness its exceeds the energy of the Bloch domain wall. The nature of this transition is not well understood. We analyze this system with the help of numerical and analytical methods. We found that it exhibits a type-II phase transition. The ground states on both sides of the transition are analyzed. For thicker samples, above the transition an asymmetric Bloch wall appears, in a 2nd order phase transition.