New Development of Mossbauer Spectroscopy

穆斯堡尔谱学发现于大约40年前，一直被用作固体物理领域的有力工具之一。本项目的目标是在穆斯堡尔谱学方面取得新的进展和成果，并为纳米级细粒子科学等材料科学和锕系元素科学做出贡献。我们在以下研究项目中开发了穆斯堡尔谱。特别要强调的是，同步辐射核共振散射光谱学的最新发展和应用，对于该光谱学在材料科学中的进一步发展是十分重要和必要的.铁氧氢氧化物的穆斯堡尔谱研究在自然环境中，钢铁表面腐蚀产物主要由α-FeOOH针铁矿、β-FeOOH赤铁矿和γ-FeOOH鳞铁矿等铁氧氢氧化物组成。我们对这些氢氧化物进行了穆斯堡尔谱测量，并确定了这些化合物的相对量 ...更多信息 这是钢铁表面的锈。研究结果已在国际会议上发表.纳米级微粒的穆斯堡尔谱学研究本文对硼包覆Fe微粒和SiO_2包覆FePt微粒进行了穆斯堡尔谱测量。结果表明，硼包覆后的Fe为完整的bcc-Fe，退火后的FePt微粒为具有四方晶系结构的四方L1_0 FePt有序合金.在<181>SPring 8中用外差法成功地观测到了新近发展起来的同步辐射核共振散射。利用SPring 8中的同一装置，我们首次成功地观测到<181>了旋转楔形有机玻璃圆盘对^ Ta核共振光子的相位调制。同步辐射核共振散射的观测为高能区相位调制、频率调制等超高分辨光学的研究开辟了新的领域.穆斯堡尔谱学在锕系元素科学中的应用^<237>Np和^<238>U是非常重要的锕系元素。近年来，在一些锕系化合物如NpFeGa_5中发现了新的磁性和超导电性。在东北大学和日本原子力研究机构的合作下，<57>对NpFeGa_5进行了穆斯堡尔谱测量，详细讨论了其磁性，并在国际会议上发表。少

Mossbauer spectroscopy was discovered about 40 years ago and has been used as one of the powerful tools in the field of solid-state physics. This project aims to get new developments and achievements in this Mossbauer spectroscopy and to contribute in material science like the nanometer-sized fine particle science and also for the actinide science. We have developed Mossbauer spectroscopy in the following research projects. Especially, we have to emphasize that the recent development and application of the nuclear resonant scattering with synchrotron radiation is quite important and essential for the further progress of this spectroscopy in material science.1. Mossbauer spectroscopic study of iron oxyhydroxidesCorrosion products formed on steel surfaces exposed to nature environment consist of oxyhydroxides like α-FeOOH Goethite, β-FeOOH Akaganeit and γ-FeOOH Lepidocrocite. We performed Mossbauer measurements for these oxyhydroxides and determined relative quantities for these compound … More s for the rust on the steel surface. These results obtained was reported and published in international conference.2. Mossbauer spectroscopic study of nano-meter-sized fine particlesMossbauer measurements have been performed for the boron-coated Fe fine particles and SiO_2 coated FePt fine particles. Results obtained clearly show that the B-coated Fe is perfect bcc-Fe and annealed FePt fine particles are tetragonal L1_0 FePt ordered alloy having tetragonal structure.3. Newly developed nuclear resonant scattering with synchrotron radiation^<181>Ta nuclear resonant scattering with synchrotron radiation was successfully observed using heterodyne method in SPring8. Using a same facility installed in SPring8,we have succeeded a first observation of the phase modulation of ^<181>Ta nuclear resonant photons by a rotating wedge shaped Lucite disk. This observation by the nuclear resonant scattering with synchrotron radiation make it possible to open the new field of the ultra-high resolution optics like phase and frequency modulations in high energy region.4. Application of the Mossbauer spectroscopy to the actinide science^<237>Np and ^<238>U are very important actinide elements. Recently novel magnetism and superconductivity have been discovered in some actinide compounds, like NpFeGa_5. Under the collaboration with Tohoku University and Japan Atomic Research Agency, ^<57>Fe Mossbauer measurements have been performed for NpFeGa_5 and discussed its magnetic propertied in detail and published in International conference. Less