X ray inelastic scattering spectroscopy for electron momentum density in solids

用于测量固体中电子动量密度的 X 射线非弹性散射光谱

基本信息

批准号：
62460031
负责人：
SHIOTANI Nobuhiro
金额：
$ 4.03万
依托单位：
東京水産大学 (1989)The Institute of Physical and Chemical Research (1987-1988)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1989
项目状态：
已结题

项目摘要

Compton scattering measurement is a unique method to study electron momentum density distributions in matter. This work has been done mostly at Photon Factory, National Laboratory for High Energy Physics. The results obtained are as follows;1. A high resolution Comptonspectrometer for 29.5keV incident X rays.has been constructed at Beam Line 14C. It consists of a bent crystal monochromator, a Cauchois type crystal analyzer for energy analysis of Compton scattered X rays and a sheet of Imaging Plate as a position sensitive detector. The momentum resolution is 0.09 atomic units. With this Compton profiles of Si, Al and liquid Li, Na, Li-Na alloy were measured. Information on the band structure and the effects of electron-electron correlation has been obtained. The Compton profiles of LiH, Li_2O,and Li_3N were also measured and information on the bonding electrons in these compounds has been obtained.2. At Beam Line AR-NE1 another more advanced spectrometer has been constructed. This one is for 40-80keV incident X rays and consists of a quasi doubly bent monochromator and four pairs of Cauchois type analyzer and Imaging Plate. With this Compton profiles along four different crystalline axes can be measured simultaneously. The three dimensional electron momentum density map can be reconstructed from the profiles taken along various crystalline axes to get much detailed information on the band structure and the Fermi surface geometry in metals and alloys.3. Electron-spin dependent Compton profiles of Fe and Ni single crystals were measured and compared with the band theoretical results. One of the conclusions obtained is that the momentum-wavefunctions of the magnetic electrons in these metals are well described by the band theory. It has been demonstrated that elliptically polarized synchrotron radiation X rays are quite useful to study magnetic properties of ferromagnetic materials.

康普顿散射测量是研究物质中电子动量密度分布的独特方法。这项工作主要是在高能物理国家实验室光子工厂完成的。得到的结果如下： 1． Beam Line 14C 建造了一台用于 29.5keV 入射 X 射线的高分辨率康普顿光谱仪。它由弯曲晶体单色仪、用于康普顿散射X射线能量分析的Cauchois型晶体分析仪和作为位置敏感探测器的成像板组成。动量分辨率为0.09原子单位。利用该康普顿分布测量了 Si、Al 和液态 Li、Na、Li-Na 合金。已经获得了有关能带结构和电子-电子相关效应的信息。还测量了LiH、Li_2O和Li_3N的康普顿分布，获得了这些化合物中成键电子的信息。 2． Beam Line AR-NE1 建造了另一台更先进的光谱仪。该装置适用于 40-80keV 入射 X 射线，由准双弯单色仪和四对 Cauchois 型分析器和成像板组成。利用这种方法，可以同时测量沿四个不同晶轴的康普顿分布。三维电子动量密度图可以根据沿不同晶轴的剖面重建，以获得有关金属和合金中的能带结构和费米表面几何形状的详细信息。 3．测量了 Fe 和 Ni 单晶的电子自旋相关康普顿分布，并与能带理论结果进行了比较。获得的结论之一是能带理论很好地描述了这些金属中磁电子的动量波函数。事实证明，椭圆偏振同步加速器辐射X射线对于研究铁磁材料的磁性能非常有用。