Effect of the location of Mn sites in ferromagneticGa1−xMnxAson its Curie temperature

K. M. Yu, W. Walukiewicz, T. Wojtowicz, I. Kuryliszyn, X. Liu, Y. Sasaki, J. K. Furdyna
2002 Physical Review B (Condensed Matter)  
We report a strong correlation between the location of Mn sites in ferrromagnetic Ga 1-x Mn x As measured by channeling Rutherford backscattering and by particle induced x-ray emission experiments and its Curie temperature. The concentrations of free holes determined by electrochemical capacitance-voltage profiling and of uncompensated Mn ++ spins determined from SQUID magnetization measurements are found to depend on the concentration of unstable defects involving highly mobile Mn
more » ... . This leads to large variations in T C of Ga 1-x Mn x As when it is annealed at different temperatures in a narrow temperature range. The fact that annealing under various conditions has failed to produce Curie temperatures above ~110K is attributed to the existence of an upper limit on the free hole concentration in low-temperature-grown Ga 1-x Mn x As.
doi:10.1103/physrevb.65.201303 fatcat:tmwcrd4iufgsrkudr43jsczfie