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

Abstract

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 [Gd2C]2+·2e− electride with hydrogens and subsequent dehydrogenation of the canted antiferromagnetic Gd2CHy (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$$\bar{3}$$ 3 ¯ 1m structured Gd2CHy, restoring the original ferromagnetic state of the R$$\bar{3}$$ 3 ¯ m structured [Gd2C]2+·2e− electride. This variable density of magnetic quasi-atomic IAEs enables the quantum manipulation of floating electron phases on the electride surface.

Topochemical Fluoride Exchange Reaction with Anionic Electrons toward Fluoride-Ion Conduction in Layered Ba2–xAxNF1–x (A = Na, K)

“…This diamagnetism was confirmed by the negative magnetic susceptibility of BKNF(0.2) at 30 K and above (Figure S12). This is natural because our samples are composed of nonmagnetic elements such as Ba, K, N, and F, which is sharp contrast to electrides with partially electron-filled d- and f-orbitals that result in a strong electrostatic interaction with anionic electrons. , The diamagnetism has also been observed for other fluoride-ion conductors such as PbF 2 and La 0.9 Ba 0.1 F 2.9 (Figure S13). Thus, BKNF(0.2) after fluorination was concluded to be an almost pure fluoride-ion conductor.…”

Electronic correlations and intrinsic magnetism of interstitial quasi-atomic states in Li8Au electride

“…It has been recently discovered that some electrides may possess a specific type of intrinsic magnetism unrelated to the electronic subsystem of atoms. 19,25–32 However, understanding the relevance of many-body effects in the subsystem of electronic interstitial states, as well as the mechanisms of formation of their intrinsic magnetic moments in various electrides, remains to be elucidated.…”