Structural and magnetic properties of nanoclusters formed in III-V semiconductors

16th International Conference on X-ray Absorption Fine Structure

Lawniczak-Jablonska, Krystyna^1 ; Wolska, Anna^1 ; Klepka, Marcin T.^1

Institute of Physics, Polish Academy of Science, Al. Lotnikow 32/46, Warsaw

02-668, Poland^1

关键词: After high temperature;    EXAFS studies;    Host matrices;    Magnetic ions;    Mn concentrations;    Structural and magnetic properties;    X-ray magnetic circular dichroism;    Zinc-blende structures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012100/pdf
DOI  :  10.1088/1742-6596/712/1/012100

来源: IOP

【 摘 要 】

Studies of X-ray magnetic circular dichroism (XMCD) were performed for a set of GaMnAs films with different Mn concentrations priory and after high temperature annealing (500 and 600oC). After thermal treatment, GaMnAs samples with zinc blende structure and MnAs hexagonal nano-clusters were formed. In most of the samples, both types of clusters were detected by EXAFS studies. Dependence of the orbital and the spin moments on magnetic field were calculated from XMCD data by applying the sum rule. It was shown that both moments were much larger for MnAs nano-clusters. When these inclusions are formed even in a small amount, they dominate the XMCD signal. Interestingly, in some of samples the zinc blende GaMnAs nano-clusters were observed at a surface while in the bulk of hexagonal MnAs. Therefore, the location of magnetic ions in the host matrix is crucial for their magnetic properties. This unique information can be provided by XAS and XMCD.