“Formation of a GaMn magnetic superficial layer on Mn and As co-implanted GaAs

E. DE BIASI; A. MALACHIAS; J. BETTINI; M. A. A. PUDENZI; A. DE SIERVO; M. BEHAR; R. D. ZYSLER

Workshop; X Latin American Workshop on Magnetism, Magnetic Materials and their Applications (LAW3M2010); 2010

The study of diluted magnetic scmiconductors (DMSs) has increased in the last yenrs duc to tecliriological applications. The spintronics as well magnctorecordirig media are important topics in this respcct. The possibility of tune the magnetic properties of this kiiid of sqsten-is becoines a crucial topic for the futures applications. The control over the structural properties as well as the magnetic relaxatioris parai-iieters is one of the fundamental subject. In this work we report the effect of a thin GaMn magnetic layer formed on top of As and Mn coiiiiplanted GaAs samples, after Rapid Thermal Anriealing (RTA) at 750°C. Besides this layer. MnAsbased clusters (implanted in the GaAs lattice matrix) werc detected using High Resolution Transmission Electron Microscopy. X-Ray diffraction sliows trigonal GaMn recrystalization oii the surface. Our studies have sliown that while thc MnAs clusters have a strong magnetic anisotropy. the GaMn layei- has a weaker one. but it is responsible for about 20% of the total magnetization of our sample. The cluster´s Curie temperature is around 360 K, while the correspondent to the surface layer is greater than 400 K. FMR experiments shows a week in plane anisotropy that has a four-fold spatial syminetry.