Determination of the micromagnetic parameters in (Ga,Mn)As using domain theory

Catherine Gourdon (1) , Alexandre Dourlat (1) , Vincent Jeudy (1) , Khashayar Khazen (1) , Hans Jürgen von Bardeleben (1) , L. Thevenard (2) , Aristide Lemaître (2)

1 INSP - Institut des Nanosciences de Paris
2 LPN - Laboratoire de photonique et de nanostructures

The magnetic domain structure and magnetic properties of a ferromagnetic (Ga,Mn)As epilayer with perpendicular magnetic easy-axis are investigated. We show that, despite strong hysteresis, domain theory at thermodynamical equilibrium can be used to determine the micromagnetic parameters. Combining magneto-optical Kerr microscopy, magnetometry and ferromagnetic resonance measurements, we obtain the characteristic parameter for magnetic domains $\lambda_c$, the domain wall width and specific energy, and the spin stiffness constant as a function of temperature. The nucleation barrier for magnetization reversal and the Walker breakdown velocity for field-driven domain wall propagation are also estimated.

Mots clés: Domain effects; magnetization curves; hysteresis; Magnetic semiconductors; Magnetic anisotropy; micromagnetic parameters

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Catherine Gourdon, Alexandre Dourlat, Vincent Jeudy, Khashayar Khazen, Hans Jürgen von Bardeleben, et al.. Determination of the micromagnetic parameters in (Ga,Mn)As using domain theory. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 76, pp.241301(R). ⟨10.1103/PhysRevB.76.241301⟩. ⟨hal-00176041⟩