Results

Applying a sufficiently large magnetic field across the circular plane of a half-sphere results in an initially homogeneous magnetisation pattern, and as with the sphere in section 3.5, a slight deviation at the surface resulting from the demagnetising field. This corresponds to point $a$ in figure 5.5; the homogeneous magnetisation is illustrated in figure 5.6.

Reducing the field further causes the nucleation of a vortex at around 30mT, resulting in the magnetisation drop immediately following point $a$ in figure 5.5.

The vortex core moves in the $-y$ direction while the field is reduced further (point $c$ in figure 5.5; illustrated in figure 5.8), until the vortex leaves the system and a homogeneous magnetisation in the $-x$ direction is established.