Magnetic Domains in the Ferromagnetic Semiconductor (Ga,Mn)(As,P)
Автор:Sanaz Haghgou Год: 2012 Издание:LAP Lambert Academic Publishing Страниц: 160 ISBN: 9783659122293 GaMnAs is a model system for diluted ferromagnetic semiconductors. The origin of ferromagnetism is the exchange interaction between the carriers and the Mn 3d spins with exchange constant Jpd. The phosphorous alloying of GaMnAs is used as a novel practical technique to adjust the magnetic anisotropy. It provides layers with perpendicular anisotropy with high homogeneity. The spin-stiffness constant A is determined and the field-driven domain wall dynamics is investigated using Kerr microscopy. In GaMnAsP due to the low density of defects the magnetic domains form a self-organized pattern. From its period the spin-stiffness constant A and the first neighbor effective exchange energy JMnMn are determined. JMnMn is larger than in GaMnAs. This result along with the higher spin-wave stiffness in GaMnAsP might indicate that the Jpd value is higher in GaMnAsP than in GaMnAs. The temperature dependence of A is experimentally determined and compared to the theoretical predictions. The...
