TEM characterisation of self-organised nanometric Fe islands embedded in MgO layers grown on GaAs substrates

摘要

Nowadays, the potential application of interesting properties of magnetic materials, such as giant and tunnel magnetoresistance effects, has driven the research into the hybridization of magnetic structures at mesoscopic scale with semiconductor technology for the configuration of magnetoelectronic devices [1,2]. The spontaneous formation of such structures presents obvious advantages over artificial fabrication procedures. This work deals with the characterization by transmission electron microscopy of self-organized Fe(001) islands of nanometric dimensions grown on MgO buffered GaAs(001) substrates by triode sputtering, at 700 °C. The nominal thickness of the Fe layer is in the range of 2.5A-20A. An MgO overlayer prevents Fe islands from electrical interaction, revealing this system as a potential candidate for exploring tunnel magnetoresistance effects in isolated granular systems [3,4,5].