Temperature-dependent magnetism of Fe thin films on ZnSe(001)

We present X-ray magnetic circular dichroism (XMCD) and magneto-optical Kerr effect (MOKE) data on the magnetic properties of Fe/ZnSe(0 0 1) thin films at increasing Fe coverage. The magnetic behaviour of the Fe overlayer is superparamagnetic for a coverage up to 6 monolayers whereas, above this threshold, a truly ferromagnetic phase shows up. XMCD and MOKE data show that this behaviour is substantially unchanged in the temperature range 10-300K for all the investigated coverages: these findings imply that the blocking temperature is definitely below 10 K. (C) 2007 Elsevier B.V. All rights reserved.