Dynamic Critical Behavior in Models of Ferromagnetic Gadolinium

A numerical technique combining Monte Carlo and molecular dynamics simulations is used for the first time to examine the complex critical dynamics of models of ferromagnetic gadolinium in which both strong exchange interactions and relativistic effects of several different types are taken into account. A finitesize scaling technique is used to calculate the corresponding dynamic critical exponents. The role played by isotropic dipole-dipole interaction in the critical behavior of gadolinium is evaluated. The results obtained provide an explanation for the anomalous dynamic critical behavior of gadolinium.