Remanent magnetization of a simple ferromagnet

We have measured the remanent magnetization of single-crystal EuS from ${10}^{\mathrm{-}4}$ to ${10}^4$ sec after removing an applied field. Using a recent model for magnon relaxation on finite domains, the data yield size-scaling exponents of θ=-0.10±0.02 and ζ=0.669±0.004, in excellent agreement with exact theoretical predictions. As a function of temperature, the remanent magnetization is a maximum above the Curie transition, and for some thermal histories, becomes negative in the ferromagnetic regime. The behavior is consistent with a percolation backbone that is negatively coupled to the finite domains.