Soft X-ray Absorption Spectroscopy of the Valence and Spin States of Zigzag-Antiferromagnetic FePS3
Aldrin Chang1*, Liang-Wei Lan1, Yao-Jui Chan1,4, Chia Nung Kuo2, Tin Chen1, Chih-Heng Huang1,3, Tzu-Hung Chuang3, Der-Hsin Wei3, Chin Shan Lue2, Chien-Cheng Kuo1
1Department of Physics, National Sun Yat-sen University, Kaohsiung City, Taiwan
2Department of Physics, National Cheng Kung University, Tainan City, Taiwan
3National Synchrotron Radiation Research Center, Hsinchu City, Taiwan
4Institute of Physics, Academia Sinica, Nankang, Taipei City, Taiwan
* Presenter:Aldrin Chang,
Detailed understanding of material character has ever been paramount in both fundamental and applied physics considering the ever-growing number of material candidates exhibiting diverse properties. X-ray absorption spectroscopy (XAS) offers an advantage over other techniques due to its capability in elucidating material fingerprints by showing strong resonances arising from the dipole-allowed transitions to unfilled valence states in an element-specific manner. Aside from XAS, electronic and magnetic properties of zigzag-antiferromagnet iron phosphorus trisulfide (FePS3) were probed using x-ray magnetic circular dichroism (XMCD) and x-ray magnetic linear dichroism (XMLD). The Fe2+ ions in FePS3 are arranged in a honeycomb lattice and gained a moniker as a magnetic graphene [1-3]. Likewise, it has risen as one of the promising magnetic van der Waals materials from the large family of metal phosphorus trichalcogenide system owing to its exotic magnetic ordering considering interactions longer than that of the nearest neighbor. XAS, XMCD, and XMLD was performed at room (RT) and at low temperature (LT) of around 110 K, passed lower than it’s Neel temperature of 118 K [4,5]. For the first time, it’s valency, crystal symmetry and spin state were probed using XAS techniques. Orbital anisotropy was observed in the linear dichroism predominantly due to the octahedral crystal field. The high spin state of the Fe2+ ion was verified by obtaining the branching ratio [6]. This work provides spectroscopic fingerprints of the antiferromagnet crucial for spintronic applications.

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Keywords: X-ray absorption spectroscopy, X-ray magnetic circular dichroism, X-ray magnetic linear dichroism, FePS3, zigzag-antiferromagnet