Domain growth in the two-dimensional random-exchange Ising ferromagnet
Rb2Cu0.89Co0.11F4 is studied using ac and de magnetization measuremen
ts. From a scaling analysis of the time and frequency dependences of t
he nonequilibrium part of the ac susceptibility the ferromagnetic doma
in size R(t) is found to grow according to R(t) proportional to [In t]
(1/psi), with psi = 1/4.