Structure and magnetism of MnAs nanocrystals embedded in GaAs as a function of post-growth annealing temperature
Structure and magnetism of MnAs nanocrystals embedded in GaAs as a function of post-growth annealing temperature
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嵌入 GaAs 中的 MnAs 纳米晶体的结构和磁性随生长后退火温度的变化
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
J. Gosk
中科院分区：
文献类型：
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作者：
A. Kwiatkowski;D. Wasik;M. Kamińska;R. Bożek;J. Szczytko;A. Twardowski;J. Borysiuk;J. Sadowski;J. Gosk
在Ga1−xMnxAs层生长后的热退火过程中，自组织的Ga(Mn)As纳米团簇嵌入到GaAs中。系统地研究了复合材料的结构和磁性能随退火温度的变化规律。在500℃的退火温度下，形成了小的（~ 3 nm）富锰的混锌Mn(Ga)As簇，与GaAs基体相一致。当退火温度提高到600℃时，可以制备出10 ~ 20 nm的大型nias型六方MnAs纳米晶体。磁化测量表明，纳米颗粒具有超顺磁性，阻断温度的分布取决于纳米颗粒簇的大小。还观察到一些中间顺磁性团簇（结构无序团簇）。
Self-organized Ga(Mn)As nanoclusters, embedded in GaAs, were formed during post-growth thermal annealing of Ga1−xMnxAs layers. Structural and magnetic properties of such composites were systematically studied as a function of the annealing temperature. Small (∼3 nm) Mn-rich zinc-blende Mn(Ga)As clusters, coherent with the GaAs matrix, were formed at the annealing temperature of 500 °C. An increase of the annealing temperature of up to 600 °C led to the creation of 10–20 nm large NiAs-type hexagonal MnAs nanocrystals. Magnetization measurements showed that the MnAs nanoprecipitates were superparamagnetic, with a distribution of blocking temperatures that depended on the MnAs cluster size. Some intermediate paramagnetic clusters (structurally disordered clusters) were also observed.