Effect of the location of Mn sites in ferromagnetic GaMnAs on its Curie temperature
Effect of the location of Mn sites in ferromagnetic GaMnAs on its Curie temperature
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DOI：
10.1103/physrevb.65.201303
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发表时间：
2002-01
影响因子：
3.7
通讯作者：
K. Yu;W. Walukiewicz;T. Wojtowicz;I. Kuryliszyn;X. Liu;Y. Sasaki;J. Furdyna
中科院分区：
文献类型：
--
作者：
K. Yu;W. Walukiewicz;T. Wojtowicz;I. Kuryliszyn;X. Liu;Y. Sasaki;J. Furdyna
我们报告了一个强相关性的位置Mn网站在铁磁Ga{sub 1-x}Mn{sub x}As测量沟道卢瑟福背散射和粒子诱导的X射线发射实验和它的居里温度。自由空穴的浓度由电化学电容-电压分布和SQUID磁化测量确定的未补偿Mn{sup ++}自旋的浓度被发现依赖于涉及高度移动的Mn材料的不稳定缺陷的浓度。当在较窄的温度范围内以不同温度退火时，这导致Ga{sub 1-x}Mn{sub x}As的T{sub c}变化很大。在各种条件下的退火未能产生高于{approx} 110 K的居里温度的事实归因于低温生长的Ga{sub 1-x}Mn{sub x}As中的自由空穴浓度存在上限。
We report a strong correlation between the location of Mn sites in ferromagnetic Ga{sub 1-x}Mn{sub 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{sup ++} spins determined from SQUID magnetization measurements are found to depend on the concentration of unstable defects involving highly mobile Mn interstitials. This leads to large variations in T{sub c} of Ga{sub 1-x}Mn{sub 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 {approx}110K is attributed to the existence of an upper limit on the free hole concentration in low-temperature-grown Ga{sub 1-x}Mn{sub x}As.