Magnetic quasi-atomic electrons driven reversible structural and magnetic transitions between electride and its hydrides

• Published in: Nature communications Vol. 14; no. 1; p. 5469
• Main Authors: Lee, Seung Yong, Lim, Dong Cheol, Khan, Md Salman, Hwang, Jeong Yun, Kim, Hyung Sub, Lee, Kyu Hyung, Kim, Sung Wng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.09.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/2795; 639/301/119/997; Anion exchanging; Anions; Antiferromagnetism; Atomic properties; Cations; Dehydrogenation; Electrons; Energy levels; Ferromagnetism; Filing; Gadolinium; Humanities and Social Sciences; Hydrogen; Hydrogenation; Interlayers; Ions; Magnetic moments; Magnetic transitions; Magnetism; multidisciplinary; Phase transitions; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41085-0

In electrides, interstitial anionic electrons (IAEs) in the quantized energy levels at cavities of positively charged lattice framework possess their own magnetic moment and interact with each or surrounding cations, behaving as quasi-atoms and inducing diverse magnetism. Here, we report the reversible structural and magnetic transitions by the substitution of the quasi-atomic IAEs in the ferromagnetic two-dimensional [Gd 2 C] 2+ ·2e − electride with hydrogens and subsequent dehydrogenation of the canted antiferromagnetic Gd 2 CH y ( y  > 2.0). It is demonstrated that structural and magnetic transitions are strongly coupled by the presence or absence of the magnetic quasi-atomic IAEs and non-magnetic hydrogen anions in the interlayer space, which dominate exchange interactions between out-of-plane Gd−Gd atoms. Furthermore, the magnetic quasi-atomic IAEs are inherently conserved by the hydrogen desorption from the P 3 ¯   1m structured Gd 2 CH y , restoring the original ferromagnetic state of the R 3 ¯ m structured [Gd 2 C] 2+ ·2e − electride. This variable density of magnetic quasi-atomic IAEs enables the quantum manipulation of floating electron phases on the electride surface. Interstitial quasi-atomic electrons (IQE) have shown promising magnetic elements. Here authors present the reversible hydrogenation and dehydrogenation of ferromagnetic [Gd 2 C] 2+ 2e− electride to canted antiferromagnet by reducing and restoring IQEs.