Sperl, Matthias and Torelli, P. and Eigenmann, F. and Soda, Marcello and Polesya, S. and Utz, Martin and Bougeard, Dominique and Ebert, H. and Panaccione, G. and Back, Christian (2012) Reorientation transition of the magnetic proximity polarization in Fe/(Ga,Mn)As bilayers. Phys. Rev. B 85, p. 184428.
Recently, it has been observed that thin ferromagnetic Fe films deposited on top of (Ga,Mn)As layers induce a significant proximity polarization in the (Ga,Mn)As film even at room temperature. Furthermore, it was found that a thin interfacial region of the (Ga,Mn)As film is coupled antiferromagnetically to the Fe layer. Here we report a series of combined x-ray magnetic dichroism and superconducting quantum interference device magnetometer measurements for Fe/(Ga,Mn)As bilayers where the (Ga,Mn)As layer thickness is varied between 5 and 50 nm. We find a reorientation transition of the magnetic proximity polarization as a function of the (Ga,Mn)As thickness. The data are compared to results obtained performing ab initio calculations. A varying concentration of Mn interstitials as a function of (Ga,Mn)As layer thickness is responsible for this reorientation. Furthermore, exchange bias is studied in the fully epitaxial bilayer system. We find a rather strong ferromagnetic exchange bias. The strength of the exchange bias can be estimated by using a simple partial domain wall model.
|Date:||25 May 2012|
|Institutions:|| Physics > Institute of Experimental and Applied Physics > Chair Professor Back > Group Christian Back|
Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Dominique Bougeard
|Projects:||SFB 689: Spinphänomene in reduzierten Dimensionen|
|Subjects:||500 Science > 530 Physics|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Partially|
|Deposited On:||30 May 2012 05:52|
|Last Modified:||09 Apr 2013 13:50|