Investigation of impurity motions with neutron resonance absorption method

密集脉冲喷射中子源可以在1-100 eV的能量范围内提供有用的eV中子通量，并可能产生一种中子共振吸收方法。许多重原子，如Au、Ag、Ta、U、Sb、Ba和Ho，在1 - 100电子伏的能量范围内，具有较大的中子吸收交叉部分（n， γ）反应在1 - 100电子伏。通过测量吸收的中子光谱，一般可以知道核的种类和样品中的运动。因此，预计这一新方法将在广泛的研究领域中非常有用，如一项不公正的研究和非破坏性的检测，一种新的中子共振吸收光谱仪EZO已在国家高能物理实验室的中子散射设施中得到证实，日本。有了这个光谱仪，我们成功地测量了有效温度的角度依赖性和温度依赖性。（Ty D2 eff D2） of Ta-atom in the layer compound TaS 2，并讨论TaS 2中Ta-atom状态的部分声子，我们也成功地测量了Ty D2 eff D2's of Ag-atom和I-atom in a离子导体AgI，尊重，and found that the Debye temperature of Ag-atom changes from T-D2 = 160 K to T-D2-D2 = 440 K around T= 150 K， while any change cannot be seen for I-atom.进一步说，这个方法是，为了第一次，应用于半导体中的缺陷研究（包括缺陷Sb）。In this work， the concentration of the impurity Sb in the Si-semiconductor was determined to be 1.84 x10 y D118 y D1 atoms/cm y D13 y D1.这是对化学分析结果的一个很好的结论。1.8 x10イイD118イエD1。The T2 of the impurity Sb is almost identical to that of the Sb-sample。

Intense pulsed spallation neutron sources can provide a useful eV neutron flux in the energy range 1-100 eV, and made a neutron resonance absorption method possible. Many heavy atoms, such as Au, Ag, Ta, U, Sb, Ba and Ho, have large neutron absorption cross-sections of (n, γ) reaction at the characteristic energies in the energy range 1 - 100 eV. By measuring the neutron spectrum of absorption, one can generally know the kind of nucleus and the motion in samples. Therefore, it has been expected that this new method become very useful in the wide research field such as impurity researches and non-destructive inspection.A new neutron resonance absorption spectrometer EZO was realized in the neutron scattering facility in National Laboratory for High Energy Physics, Japan. With this spectrometer, we succeeded to measure both the angular dependence and temperature dependence of effective temperatures (TィイD2effィエD2) of Ta-atom in the layer compound TaS2, and to discuss the partial phonon desity of states of Ta-atom in TaS2.We also succeeded to measure TィイD2effィエD2's of Ag-atom and I-atom in an ionic conductor AgI, respectively, and found that the Debye temperature of Ag-atom changes from TィイD2effィエD2 = 160 K to TィイD2effィエD2 = 440 K around T= 150 K, while any change cannot be seen for I-atom. Further, this method were, for the first time, applied on the study of impurity in a si-semiconductor (including impurity Sb). In this work, the concentration of the impurity Sb in the Si-semiconductor was determined to be 1.84x10ィイD118ィエD1 atoms/cmィイD13ィエD1. This is in good agreement to the result of the chemical analysis. 1.8x10ィイD118ィエD1. The TィイD2effィエD2 of the impurity Sb was almost identical to that of the Sb-sample.