Permissions for Reuse

Full figure

Fig. 1. (Color) Electrical, magnetic, and structural dependence on As:Ga for a 100  nm thick Ga_0.84Mn_0.16As film grown without rotation. Inset: substrate and source geometry. (a) Room temperature longitudinal (_xx) and Hall (_xy) conductivities, (b) Curie temperature (T_C) and saturation moment (M_sat) at 5  K, and (c) lattice constant (a_GaMnAs) for different As:Ga. Stoichiometric region is shaded gray. Inset: _xx vs anneal time, right axis is the anneal temperature. (d) HRXRD scans along -2 near the (004) substrate peak measured on stoichiometric (as-grown and annealed) and As-rich samples labeled in the figure. First citation in article

Full figure

Fig. 2. (Color) Variation in ferromagnetism and magnetotransport due to stoichiometry and postgrowth annealing for a 100  nm thick Ga_0.84Mn_0.16As film grown without rotation. (a) Magnetic moment (M) and _xx vs temperature (T). (b) M vs magnetic field (H) hysteresis loops from the stoichiometric, annealed sample at various temperatures near T_C. (c) Hysteresis loops at 5  K. (d) Resistivity (_xx) at 10  K vs H. MR at 14  T is labeled in the figure. Hall resistivity (_xy) vs H for the annealed, stoichiometric sample. First citation in article

Full figure

Fig. 3. (Color) (a) T_C vs x for stoichiometric samples of Ga_1−xMn_xAs for 0<x<0.22 from many separate nonrotated growth runs. Data are shown both for as-grown and optimally annealed samples. Lines are guides to the eye. (b) Lattice constant (a_GaMnAs) vs x from HRXRD scans as shown in Fig. 1(d). Using the model proposed by Masek et al. (Ref. 17), linear fits to our data indicate a constant fraction of interstitials (z/x, labeled in the figure) for x0.16. The blue data are for increasingly As-rich material, along the arrow. First citation in article