Remanent magnetization of a simple ferromagnet

We have measured the remanent magnetization of single-crystal EuS from 10-4 to 104 sec after removing an applied field. Using a recent model for magnon relaxation on finite domains, the data yield size-scaling exponents of =-0.100.02 and =0.6690.004, 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. © 1991 The American Physical Society.