Abstract
A simple formal model of domain wall pinning by inhomogeneities in ferromagnetic alloys is developed. Particular attention is paid to the variation of coercivity with temperature, and it is shown that the coercive field varies linearly with the temperature of observation for an idealized form of magnetic inhomogeneity. This linear variation is observed in PtCo and SmCo5 alloys and it is estimated that each inhomogeneity changes the wall energy by about 2 × 10−12 erg. The diameter of the inhomogeneities in SmCo5 is estimated to be about 34 Å.