【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

22QS0107

利用課題名 / Title

Untangling the structural, magnetic dipole, and charge multipolar orders in Ba₂MgReO₆

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

double perovskite, spin-orbit coupling,放射光/Synchrotron radiation,スピン制御/ Spin control

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)

Ronnow Henrik

所属名 / Affiliation

Ecole polytechnique federale de Lausanne (EPFL)

共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes

Jian-Rui Soh,Ivica Zivkovic

ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes

Kenji Ishii

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

QS-112：共鳴非弾性X線散乱装置

報告書データ / Report

概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)

Due to a strong coupling between spin, orbital and vibrational degrees of freedom, 5d1 double perovskites are representing an interesting avenue of research. Ba₂MgReO₆ is a 5d1 material exhibiting a magnetic transition at 18 K and a charge quadrupolar transition at 33 K. It is expected to have a quartet ground state, however, detailed specific heat measurements reveal only Rln2, indicating a doublet. In order to study its dd-excitations, we employ L₃-edge resonant inelastic x-ray scattering (RIXS) on Re ion to study the nature of its ground state and the associated excited states.

実験 / Experimental

【利用した装置】：共鳴非弾性X線散乱装置
【実験方法】
Aligned the crystal using 444 and 044 peaks, employing a two-bounce channel-cut Si(444). Cooled down to base temperature (8 K). Performed multiple energy-loss scans for various incident energies in the vicinity of the resonant frequency of 10.535 keV.

結果と考察 / Results and Discussion

Wide energy-loss scans revealed a couple of features, as seen in Fig.1. Alongside the elastic line, which has been used to properly offset all the energies, we observed a sharp absorption line around 0.5 eV. This can be assigned to the spin-orbit-coupling splitting of t_2g levels into a low-lying quartet and a high-lying doublet. A feature around 4.7 eV has a somewhat asymmetric line-shape, corresponding to the main t_2g-e_g splitting caused by the octahedral crystal field environment. At higher energies, centered around 7.5 eV, a broad feature is situated, which can be associated with a charge-transfer gap between Re and O orbitals.

図・表・数式 / Figures, Tables and Equations

Fig.1: Energy-loss scans at several incident energies

その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)

It is a pleasure to acknowledge an enormous help from Dr. Kenji Ishii for being our local contact and ensuring a very smooth experiment.

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