Establishing micromagnetic parameters of ferromagnetic semiconductor (Ga,Mn)As
arXiv:1207.0310
Abstract
(Ga,Mn)As is at the forefront of research exploring the synergy of magnetism with the physics and technology of semiconductors, and has led to discoveries of new spin-dependent phenomena and functionalities applicable to a wide range of material systems. Its recognition and utility as an ideal model material for spintronics research has been undermined by the large scatter in reported semiconducting doping trends and micromagnetic parameters. In this paper we establish these basic material characteristics by individually optimizing the highly non-equilibrium synthesis for each Mn-doping level and by simultaneously determining all micromagnetic parameters from one set of magneto-optical pump-and-probe measurements. Our (Ga,Mn)As thin-film epilayers, spannig the wide range of accessible dopings, have sharp thermodynamic Curie point singularities typical of uniform magnetic systems. The materials show systematic trends of increasing magnetization, carrier density, and Curie temperature (reaching 188 K) with increasing doping, and monotonous doping dependence of the Gilbert damping constant of ~0.1-0.01 and the spin stiffness of ~2-3 meVnm^2. These results render (Ga,Mn)As well controlled degenerate semiconductor with basic magnetic characteristics comparable to common band ferromagnets.
5 figures, supplementary information
References in corpus (13)
- Prospects of high temperature ferromagnetism in (Ga,Mn)As semiconductors
- Experimental observation of the optical spin transfer torque
- Reorientation Transition in Single-Domain (Ga,Mn)As
- Enhanced annealing, high Curie temperature and low-voltage gating in (Ga,Mn)As: A surface oxide control study
- Magneto crystalline anisotropies in (Ga,Mn)As: A systematic theoretical study and comparison with experiment
- Light-Induced Magnetic Precession in (Ga,Mn)As Slabs: Hybrid Standing-Wave Damon-Eshbach Modes
- Experimental observation of the optical spin-orbit torque
- Systematic study of Mn-doping trends in optical properties of (Ga,Mn)As
- Coherent Magnetization Precession in GaMnAs induced by Ultrafast Optical Excitation
- Unusual spin-wave population in nickel after femtosecond laser pulse excitation
- Determination of the micromagnetic parameters in (Ga,Mn)As using domain theory
- Theory of spin waves in ferromagnetic (Ga,Mn)As
- Magnetic Anisotropy, Spin Pinning and Exchange Constants of (Ga,Mn)As films