Development of Study in Magnetism using 3rd Generation SR

1. 利用第三代SRDiamond相板的亮光源进行单色x射线螺旋度快速反转实验，并在SPring-8 BL39XU上成功建立了螺旋度调制方法。该方法显著提高了x射线磁圆二色谱的精度。在项目期间，我们研究了fe -氧化物铁磁体的磁态、Mn碳化物钙钛矿的磁相变、CeSb的超磁性和ho -铁石榴石在高温下的磁态。我们在ESRF和SPring-8上进行了SR实验的合作。1998年10月在ESRF上进行了Ce/Fe和CeLa/Fe多层膜的共振磁散射，1999年2月在弹簧-8上测量了Ce/Fe和CeH/Fe多层膜的XMCD光谱的温度依赖性。在此基础上讨论了层内和层间的磁性结构。本文对3d-4f金属间化合物中稀土元素的l边XMCD谱进行了理论解释。计算光谱考虑了4f-5d原子内交换相互作用、5d波函数收缩和3d-5d原子间相互作用，较好地再现了实验结果。从对光谱精细结构影响的角度讨论了各种磁性材料中的固态效应。计算了Hubbard模型中的谐振x射线发射光谱，并研究了电子相关效应。8年春季在BL39XU上安装了最大10T超导磁体，成功记录了高场低温下的XMCD谱。针对高压条件，设计并制造了由金刚石砧池和氦气闭式循环制冷机组成的系统。采用简化炉对XMCD进行了高温测量。研究人员交换项目期间冈山大学和格勒诺布尔大学共交换了12名研究人员。在交流项目期间进行的讨论对于磁学领域以及SR仪器开发领域的合作伙伴来说非常富有成果。少

1. Experiments using brilliant light source of 3rd generation SRDiamond phase plate was applied to fast helicity reversal of the monochromatized X-ray, and the helicity-modulation method was successfully established at SPring-8 BL39XU.Accuracy of X-ray magnetic circular dichroism (XMCD) spectrum has been remarkably improved by this method. In the term of project, we have studied magnetic states in Fe-oxides ferrimagnets, magnetic phase transitions in Mn carbide perovskites, metamagnetism in CeSb, and magnetic states in Ho-iron-garnet at higher temperatures.2. Collaboration in SR experimentWe have collaborated with each other for SR experiments at ESRF and SPring-8. In October, 1998, resonant magnetic scattering in Ce/Fe and CeLa/Fe multilayers was made at ESRF, and in February, 1999, temperature dependence of XMCD spectrum in Ce/Fe and CeH/Fe multilayers was measured at SPring-8. The intra-layer and inter-layer magnetic structures were discussed on the basis of the observations.3. Theo … More retical study on spin-electronic statesTheoretical interpretation has been formulated on the L-edges XMCD spectrum of rare-earth (RE) elements in 3d-4f intermetallic compounds. The calculated spectrum well reproduced the experiment by taking into account 4f-5d intra-atomic exchange interaction, shrinkage of 5d wave function, and 3d-5d inter-atomic interaction. Solid-state effect in the various magnetic materials is also discussed from the view point of influence on fine structure in the spectrum. Resonant X-ray emission spectroscopy in Hubbard model was also calculated and electron correlation effect was studied.4. Development of experimental instrumentsA superconducting magnet with 10T maximum was installed on BL39XU in Spring-8, and the XMCD spectrum under high-field and low temperature was successfully recorded. For the condition of high-pressure, a system composed of a diamond-anvil-cell and a He-gas closed cycle refrigerator was designed and fabricated. A simplified furnace was used for the XMCD measurement at high temperatures.5. Exchange of researchersTwelve researchers have totally exchanged between Okayama and Grenoble universities in the term of project. The discussions which taken place during the exchange program were very fruitful for the partner in the field of magnetism as well as in the field of development of SR instrumentation. Less