Calculation of intrinsic coercivity of magnetic domain walls in perfect crystals

The critical field strength at which a classical domain wall moves through a perfect ferromagnetic crystal of simplified structure is calculated as a function of the ratio between anisotropy energy
K
and ferromagnetic coupling energy
C
, taking into account the discrete nature of the spins. When
K
approaches
C
intrinsic wall pinning becomes appreciable with critical fields approaching the anisotropy field when
K \gg C
. For
K/C \geq 2/3
, the wall has a thickness of one atomic distance and thus resembles a ferroelectric wall.