  (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.
