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Spin polarization in the phase diagram of a Li-Fe-S system.

ABSTRACT: Divalent and trivalent states of Fe ions are known to be stable in inorganic compounds. We focus a novel Li_xFeS₅ cathode, in which the Li content (x) changes from 2 to 10 by an electrochemical technique. As x increases from 2, a Pauli paramagnetic conductive Li₂FeS₅ phase changes into a superparamagnetic insulating Li₁₀FeS₅ phase. Density functional theory calculations suggest that Fe⁺ ions in a high-x phase are responsible for ferromagnetic spin polarization. Reaching the monovalent Fe ion is significant for understanding microscopic chemistry behind operation as Li-ion batteries and the original physical properties resulting from the unique local structure.

SUBMITTER: Takami T

PROVIDER: S-EPMC6934561 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

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Spin polarization in the phase diagram of a Li-Fe-S system.

Takami Tsuyoshi T Takeuchi Tomonari T Fukunaga Toshiharu T

Scientific reports 20191227 1

Divalent and trivalent states of Fe ions are known to be stable in inorganic compounds. We focus a novel LixFeS5 cathode, in which the Li content (x) changes from 2 to 10 by an electrochemical technique. As x increases from 2, a Pauli paramagnetic conductive Li2FeS5 phase changes into a superparamagnetic insulating Li10FeS5 phase. Density functional theory calculations suggest that Fe+ ions in a high-x phase are respons ...[more]

PMID: 31882639

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