Magnetic cluster phases of Mn-interstitial-free (Ga,Mn)As

We report an investigation of magnetic cluster phases of (Ga,Mn)As of varying dosages formed by Mn ion implantation followed by pulsed-laser melting (II-PLM). A systematic study of zero-field-cooled and field-cooled magnetization along several high-symmetry crystallographic directions reveals the presence of magnetic cluster-like phases, and manifests an unambiguous in-plane uniaxial anisotropy in all samples. Since such anisotropy has been previously seen in (Ga,Mn)As grown by molecular beam epitaxy, its observation in (Ga,Mn)As prepared by II-PLM suggests that it is an intrinsic property of (Ga,Mn)As rather than a consequence of a specific growth method. Our results also indicate a unique uniaxial component along [1 10] for the magnetic cluster phase at intermediate Mn dosage indicating that composition as well as processing may determine the details of the magnetic anisotropy in (Ga,Mn)As.