【公開日：2023.08.01】【最終更新日：2023.04.27】
課題データ / Project Data
課題番号 / Project Issue Number
22QS0102
利用課題名 / Title
Imaging of hyperfine interactions
利用した実施機関 / Support Institute
量子科学技術研究開発機構 / QST
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions（副 / Sub）その他/Others
キーワード / Keywords
hyperfine interactions,メスバウアー分光,放射光/Synchrotron radiation
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Szymanski Krzysztof
所属名 / Affiliation
Faculty of Physics, University of Bialystok
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
Dariusz Maciej Satuła,Wojciech Olszewski,Paweł Butkiewicz
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
Takaya Mitsui,Kosuke Fujiwara
利用形態 / Support Type
（主 / Main）共同研究/Joint Research（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
Mössbauer spectroscopy is useful tool in non-invasive characterization of materials by relying on nuclear probes imbedded in the sample. It allows to access hyperfine structure (hfs) parameters that provide quantitative information on the electronic properties of matter, magnetic moment, magnetic ordering, local symmetry, and the charge of the electronic state. Therefore, knowledge of complete map of hfs is essential tool for studies of condensed matter. However, currently the determination of hfs from the shape of Mössbauer spectra, is at best ambiguous - multiple values of hfs parameters lead to the same spectrum [1].
Recently we have shown [2], that in the case of the most popular nuclear probe 57Fe mentioned ambiguity can be eliminated by using multiple Mössbauer spectra measured with different orientation of the crystallographic (or sample) axis with respect to the beam direction. So, the aim of the experiment is to demonstrate the possibility of hfs parameters imaging with a synchrotron source, using the nuclear resonant scattering of the 57Fe isotope. By doing so our method will provide spectroscopists the ability to characterize materials in a more complete and useful fashion.
実験 / Experimental
【利用した装置】：放射光メスバウアー分光装置
【実験方法】
Measurements were performed in transmission mode on 57Fe reference sample and 57FeB single crystal in ambient conditions with unpolarized beam. In both cases measurements without external magnetic field acting on the sample were obtained. Each Mössbauer spectrum was measured with different sample orientations, covering as much of 4π solid angle as possible.
All the obtained results are valid only under condition of stationary absorber in respect to the holder. For this reason, Laue diffraction patterns had to be measured before and after Mössbauer experiment, to have evidence that during whole measurement series the absorber remained in its initial position.
結果と考察 / Results and Discussion
In the first stage of the experiment the 57Fe polycrystalline grain with diameter approximately 50 μm was mounted in the sample holder. To ensure the existence of single magnetic domain within the sample the external magnetic field with well-known direction was applied. Mössbauer measurements were carried out with different orientations of the incident beam in the relation to the sample plane. All possible beam directions are presented in Figure 1a). For clarity just examples of measured spectra for two different set of angles are shown in Figure 1b).
Mössbauer measurements of 57Fe with unpolarized radiation show Zeeman sextet in which relative line intensities are I1:I2:I3:I4:I5:I6 = 3:z:1:1:z:3, where the z parameter depends directly on the orientation beam direction with respect to the investigated sample. Analysis of measurements of this sample will serve as reference.
In the next step, the same experimental steps were performed for a 57FeB single crystal sample. Possible beam orientations in respect to the sample plane are presented in Figure 2a) and example of obtained spectra in Figure 2b).
The 57FeB single crystal is magnetically ordered at room temperature so its Mössbauer spectrum is composed of one sextet. Additionally, the crystal has low symmetry and is characterized by a relatively large electric field gradient, so it is a perfect candidate for testing the proposed concept of the determination of full set of hfs parameters in the simplest case of sample with one crystallographic position of iron atoms. Unfortunately, due to the high 57Fe enrichment and thus by large line widths the details of the spectra are not well resolved. Nevertheless, changes in the shape of spectra are noticeable (see Figure 2b)) making possible their analysis. To get the quantitative information from this analysis a transmission integral approach in data treatment will be required. The analysis of the obtained data is in progress.
図・表・数式 / Figures, Tables and Equations
Fig. 1 (a) All the different directions of the beam in respect to the 57Fe sample plane, (b) example of Mössabuer spectra
Fig. 2 (a) All the different directions of the beam in respect to the 57FeB sample plane. Red, green and blue short arrows represent the main crystallographic axes a, b and c, respectively. Long dark blue arrow shows the direction of external magnetic field acting on the sample. (b) example of Mössabuer spectra
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
・References:
[1] S. W. Karyagin Fiz. Tverd. Tela (Leningrad) 8 (1966) 493; Sov. Phys. Solid State 8 (1966) 391.
[2] K. R. Szymański, Eur. Physics Journal B 91 (2018) 292.
・Acknowledgements:
We thank Takaya Mitsui and Kosuke Fujiwara for the assistance during the experiment.
・Funding:
This work was supported by the National Science Centre (grant OPUS no 2018/31/B/ST3/00279).
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件