Study of Magnetic Properties and Local Structures in Discontinuous-CoFe--ZnO Multilayers.

In this study, we have investigated the magnetic properties and local structures of discontinuous-Co70Fe30(x Å)-Zno multilayers (MLs). With the variation of Co70 Fe30 nominal thickness, the phase transition from diluted magnetic semiconductor (DMS) phase, x = 1 ML, to granular phase, x = 5, and 9 MLs, is indicated from the measurements of magnetization versus temperature behavior and extended X-ray absorption fine structure (EXAFS) on Co or Fe K-edge. The analysis of EXAFS at Zn K-edge shows the reduction of Co coordination numbers with the increasing CoFe thickness. This result demonstrates that the CoFe grain size plays an important role in the formation of DM8 and is greatly critical for multilayer growth technique. [ABSTRACT FROM AUTHOR]