Lecture Diego Rubi
|03 juli 2006||FWN-Building 5114.0004, Nijenborgh 4, 9747 AG, Groningen|
|Affiliation:||Institut de Ciencia de Materials de Barcelona|
|Title:||Tailoring the ferromagnetic interaction of functional materials for spintronics: double perovskites and ZnO-based diluted magnetic semiconductors|
|Date:||Mon Jul 3, 2006|
|Telephone:||+31 50 363 4565|
The functionality of spintronics devices requires the development and engineering of spin-polarized sources, triggering the search of ferromagnetic materials with magnetic order above room temperature and large spin polarization. Among these materials, the double perovskite Sr2FeMoO6 has raised a lot of interest due to its high Curie temperature ( approx. 400 K) and room temperature magnetoresistance. Here we present recent advances on the understanding and tailoring of the magnetic interaction of Fe-Mo based double perovskites. We have successfully explored two different approaches to increase the Curie temperature of these compounds: the substitution of the A-site with a trivalent lanthanide, and the introduction of Fe-excess in the Fe-Mo sub-lattice. In particular, we will describe the properties of the electron doped (LA)2FeMoO6 (L=La,Nd; A=Sr,Ca) and the Fe-rich AFe1+xMo1-xO6 (x>0) series.
The second part of the talk will be focused on very recent progresses on the study of ZnO-based diluted magnetic semiconductors (DMS). We will show that the ferromagnetism of both Co and Mn-doped ZnO can be switched on and off by consecutive annealings at low temperatures under suitable atmospheres. These results convincingly support the defect-mediated character of the ferromagnetic interaction of this interesting DMS system.
|Laatst gewijzigd:||22 oktober 2012 14:30|