Journal of Statistical Physics, Vol. 27, No. 2, 1982. p. 407-417.
A system of particles with spin interaction in an external magnetic field is studied using a general formalism applicable to the solid, liquid, or glassy state. Explicit results are given in the mean spherical, LOGA, and EXP approximations. The Laplace transform of the wall-particle correlation function near a surface is obtained. From it, analytical expressions for the orientational density profile are derived and used to calculate the magnetization and magnetic susceptibility in the bulk. Magnetostriction is also discussed.