69,71Ga and 14N high-field NMR of gallium nitride films
69,71Ga and 14N high-field NMR of gallium nitride films
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氮化镓薄膜的 69,71Ga 和 14N 高场核磁共振
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
J. Yesinowski
中科院分区：
文献类型：
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作者：
J. Yesinowski
用高场（11.7T）的~（69）、~（71）Ga和~（14）N NMR对HVPE制备的不同缺陷水平的氮化镓厚膜进行了表征。最高质量的膜产生最尖锐的NMR峰，从该峰可以从作为膜取向的函数的研究中导出高度精确的NMR参数，即核四极耦合常数（NQCC）、各向同性化学位移和化学位移各向异性。高质量的薄膜（较大的X射线摇摆曲线宽度）表现出显着更广泛的71 Ga卫星过渡峰与较长的T2弛豫时间，和额外的高频肩或峰的中心过渡。在质量较差的膜中，14 N双合线的线宽也更宽。高氧含量薄膜的~（71）Ga谱显示了一个新的高频中心跃迁峰，其T_1很短。在所有情况下的高频峰可能是由于导电电子产生的奈特位移。（© 2005 WILEY-VCH Verlag GmbH & Co. KGaA，魏因海姆）
Gallium nitride thick films produced by HVPE having varying levels of defects have been characterized by 69,71Ga and 14N NMR at high field (11.7 T). The highest quality film yields the sharpest NMR peaks, from which highly accurate NMR parameters, viz. nuclear quadrupole coupling constants (NQCC), isotropic chemical shifts and chemical shift anisotropies, could be derived from studies as a function of film orientation. Poorer quality films (larger X-ray rocking curve widths) exhibit markedly broader 71Ga satellite transition peaks with a longer T2 relaxation time, and additional high-frequency shoulders or peaks for the central transitions. The linewidths of the 14N doublet are also broader in the poorer quality films. The 71Ga spectra of films containing high oxygen levels show a new high-frequency central-transition peak with a very short T1. The high-frequency peaks in all cases may be due to Knight shifts arising from conduction electrons. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)