Magnetic Structural Analysis of Magnetic Thin Films Artificially Modulated on a Monatomic Layer scale by Polarized Neutron Scattering Technique

1.三轴中子分光计TAS-1和中子反射计SUIREN的极化中子选项已得到改进。该谱仪和反射计已安装在日本原子能机构（JAEA）的JRR-3研究堆上，能够对散射体积很小的磁性薄膜进行详细的磁结构分析.利用TAS-1和CRYOPAD（Cryogenic Polarization Analysis Device）相结合的方法，成功地对Cr/Sn多层膜中的自旋密度波进行了球偏振分析。CRYOPAD可以测量散射中子极化的三个分量，从而可以确定反铁磁介质中复杂的自旋结构.研究人员和其他合作者合成的磁性薄膜已经使用TAS-1和SUIREN进行了研究。例如，<16>用TAS-1进行最佳氮化处理的α"-Fe_ N_2薄膜中不存在巨磁矩。α"-Fe_ N_2的巨磁矩<16>是一个长期的问题.用努森池成功地沉积了钌（Ru），沉积速率为0.001nm/sec。在1985 C.钌是提高磁记录读头性能的关键材料。由于Ru的高熔点，使用K电池的沉积从未尝试过，尽管通常期望使用K电池进行高质量的外延生长。我们现在要进行下一步，使用K电池和货车德瓦尔斯外延方法合成高质量的外延膜。

1. Polarized neutron options for a triple-axis neutron spectrometer, TAS-1, and a neutron reflectometer, SUIREN, have been improved. The spectrometer and reflectometer are installed at research reactor JRR-3 of Japan Atomic Energy Agency (JAEA) and are now capable of the detailed magnetic structural analysis of the thin magnetic films whose scattering volumes are very tiny.2. Spherical polarization analysis of an artificially confined spin-density wave in Cr/Sn multilayer has been successfully given using combination of TAS-1 and CRYOPAD (CRYOgenic Polarization Analysis Device). CRYOPAD can measure the three components of the polarization of scattered neutrons, and consequently can determine complicated spin structures in antiferromagnetic specimen.3. Magnetic films synthesized by the investigators and the other collaborators have been investigated using TAS-1 and SUIREN. For example it has been revealed that no giant magnetic moment exists in α"-Fe_<16>N_2 thin films with an optimum nitrization using TAS-1. The giant magnetic moment in α"-Fe_<16>N_2 had been a long term issue.4. Deposition of Ruthenium (Ru) has been succeeded using the Knudsen Cell with the rate of 0.001nm/sec. at 1985 C. Ru is a key material for improvement of the performance of magnetic recoding read-head. The deposition using K cell had never been tried because of the high melting point of Ru although high-quality epitaxial growth was generally expected using the K cell. We are now going to the next step to synthesize high-quality epitaxial films using the K cell and the van der Waals epitaxy method.