Development of high precision THz-ESR system by using repealing pulsed magnetic fields

利用相斥脉冲磁场开发高精度太赫兹-ESR系统

• 批准号: 13554011
• 负责人: NOJIRI Hiroyuki
• 金额: $ 9.02万
• 依托单位: OKAYAMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13554011/
• 关键词: Ultra-high magnetic fields; Extreme condition; ESR; Terahertz wave; Pulsed magnetic fields; 繰り返しパルス磁場; 強磁場; テラヘルツ; ナノ磁性体; サブミリ波

A high precision terahertz ESR system has been developed by using a repeating pulsed magnetic field. The system is capable of generating pulsed magnetic fields up to 30 T every two seconds. The drastic improvement of signal to noise ratio is achieved by the signal averaging technique. The ratio becomes at least 50 times higher than that of the conventional ESR spectrometer by using a single shot type pulse field. The maximum frequency up to 3 THz can be used and it is extremely higher than that of the commercial W-band ESR spectrometer. Moreover, the efficiency defined by the possible number of scans par unit time is much larger than that of ESR spectrometer using superconducting magnets. The typical resolution of the present system is 10 gauss in simple hardware averaging method. The resolution ca be improved to 1 gauss by using a software averaging by suing a peak picking process. Test experiments have been made on a ladder compound and a micro single crystal of nano-magnetic cluster. Even a very weak forbidden transition can be observed by present system. The present result leads to the application of a repeating pulsed magnetic field for various types of spectroscopy such as Raman scattering or X-ray spectroscopy for solid state.

通过使用重复的脉冲磁场，已经开发出高精度的Terahertz ESR系统。该系统能够每两秒钟产生最多30吨的脉冲磁场。信号与噪声比的急剧改善是通过信号平均技术实现的。通过使用单个Shot类型脉冲场，该比率比常规ESR光谱仪的比率比常规ESR光谱仪高出50倍。最大频率高达3THz，并且比商用W波段ESR光谱仪的最高频率非常高。此外，使用超导磁体的扫描单位时间数量所定义的效率比ESR光谱仪的效率大得多。本系统的典型分辨率是简单硬件平均方法中的10个高斯。通过起诉峰采摘过程，通过使用平均软件来将分辨率CA提高到1高斯。已经在梯子化合物和纳米磁性簇的微晶体上进行了测试实验。即使是非常弱的禁止过渡也可以通过当前系统观察到。目前的结果导致将重复的脉冲磁场应用于各种类型的光谱法，例如拉曼散射或X射线光谱固体。

项目成果

M.Motokawa, H.Ohta, H.Nojiri: "The role of ESR in research of low dimensional antiferromagnet"J.Phys.Soc.Jpn.. 72.Suppl.B. 1-11 (2003)

M.Motokawa、H.Ohta、H.Nojiri：“ESR 在低维反铁磁体研究中的作用”J.Phys.Soc.Jpn.. 72.Suppl.B。

T.Sakon, K.Koyama, M.Motokawa, H.Nojiri, T.Asano, Y.Ajiro: "Electron spin resonance measurement at ultralow temperatures"Physica B. 329-333. 1629-1631 (2003)

T.Sakon、K.Koyama、M.Motokawa、H.Nojiri、T.Asano、Y.Ajiro：“超低温下的电子自旋共振测量”Physica B. 329-333。

T.Asano, H.Nojiri, Y.Inagaki, T.Sakon, J-P.: "ESR study of sine-Gordon excitations in S=1/2 antiferromagnet chain : copper benzoate"Physica B. 329-333. 1213-1214 (2003)

T.Asano、H.Nojiri、Y.Inagaki、T.Sakon、J-P.：“S=1/2 反铁磁体链中正弦戈登激发的 ESR 研究：苯甲酸铜”Physica B. 329-333。

H.Nojiri, T.Taniguchi, Y.Ajiro, A.M.Muller, B.Barbara: "Quantum dynamics of molecular magnets in ultra-fast sweeping magnetic Fields"Physica B. 346-347. 216-220 (2004)

H.Nojiri、T.Taniguchi、Y.Ajiro、A.M.Muller、B.Barbara：“超快扫描磁场中分子磁体的量子动力学”Physica B. 346-347。

H.Hachisuka, K.Awaga, T.Yokoyama, T.Kubo, T.Goto, H.Nojiri: "Structure and magnetic properties of single-molecule magnet Mn_<11>Cr : Magneization manipulation and internal field in the mixed crystals of Mn_<11>Cr and"Physical Review B. (in print). (2004)

H.Hachisuka、K.Awaga、T.Yokoyama、T.Kubo、T.Goto、H.Nojiri：“单分子磁体 Mn_<11>Cr 的结构和磁性：混合晶体中的磁化操纵和内场