A Bloch wall is a narrow transition region at the boundary between magnetic domains, over which the magnetization changes from its value in one domain to that in the next. The magnetization rotates along an axis that is perpendicular to the plane of the wall (see image) unlike the Néel wall where the rotation axis is parallel to the plane of the wall. An example of a Néel wall transition is shown in the animation below.
Bloch walls are named after the physicist Felix Bloch.
Bloch domain walls appear in bulk materials, i.e. when sizes of magnetic material are considerably larger than domain wall width (according to the width definition of Lilley [1]). In this case energy of the demagnetization field does not impact the micromagnetic structure of wall. The mixed cases are possible as well when demagnetization field changes the magnetic domains (magnetization direction in domains) but not the domain walls[2].