Local fields and conduction electron behavior at impurity sites in ZnO

用时间微分扰动角关联（TDPAC）方法，以~（111）Cd（<-111）In）为探针，研究了不同浓度In掺杂ZnO的局域结构。 铟浓度依赖的TDPAC光谱表明，由In离子形成的局部结构是敏感的，它们在系统中的人口。 光谱分析结果表明：微量In离子掺杂时，可替代Zn离子而不产生任何缺陷，In离子在ZnO中局部形成广泛分散的微观独特结构，In离子掺杂浓度为0.05at.%或更高，明显表明In离子在ZnO中的溶解度极限;并且在进一步浓缩至10at.%的样品中形成In 2 O3类化合物。 我们还成功地观察到传导电子散射的探针核组成的独特的结构，这是一致的散装样品中观察到的电导率。

Local structures in zinc oxide (ZnO) doped with In ions at various concentrations were investigated by means of the time-differential perturbed angular correlation (TDPAC) method with the 111Cd(<-111In) probe. Indium-concentration dependence of the TDPAC spectra suggests that the local structures formed by In ions are sensitive to their population in the system. The results obtained by spectral analyses are the followings: In ions can substitute for Zn ions without generating any defects in their vicinity when doped with a trace amount; they locally form microscopic unique structures widely dispersed in ZnO at the In concentration of 0.05 at.% or higher, evidently indicating the solubility limit of In ions in ZnO; and In2O3-like compounds are formed in samples with further concentrated In as high as 10 at.%. We also successfully observed conduction electron scattering at the probe nuclei composing the unique structure, which is consistent with conductivity observed for bulk samples.