  The Fokker-Planck equation derived by Brown for the probability density
function of the orientation of the magnetic moment of single domain particles
is one of the basic equations in the theory of superparamagnetism. Usually this
equation is solved by expanding the solution into a series of spherical
harmonics, which in this case is a complex and cumbersome procedure. This
article presents the implementation procedure and some results of the numerical
solution of the Fokker-Planck equation using the finite element method. A
method for creating a sequence of triangular grids on the surface of a sphere
based on an inscribed icosahedron is described. The equations of the finite
element method are derived and examples of numerical solutions are presented.
The processes of magnetization and demagnetization under heating of a particle
with cubic magnetic anisotropy are simulated.
