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Controlling the Superconductivity of Nb2PdxS5 via Reversible Li Intercalation.

Published version
Peer-reviewed

Repository DOI


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Abstract

The Nb2PdxS5 (x ≈ 0.74) superconductor with a Tc of 6.5 K is reduced by the intercalation of lithium in ammonia solution or electrochemically to produce an intercalated phase with expanded lattice parameters. The structure expands by 2% in volume and maintains the C2/m symmetry and rigidity due to the PdS4 units linking the layers. Experimental and computational analysis of the chemically synthesized bulk sample shows that Li occupies triangular prismatic sites between the layers with an occupancy of 0.33(4). This level of intercalation suppresses the superconductivity, with the injection of electrons into the metallic system observed to also reduce the Pauli paramagnetism by ∼40% as the bands are filled to a Fermi level with a lower density of states than in the host material. Deintercalation using iodine partially restores the superconductivity, albeit at a lower Tc of ∼5.5 K and with a smaller volume fraction than in fresh Nb2PdxS5. Electrochemical intercalation reproduces the chemical intercalation product at low Li content (<0.4) and also enables greater reduction, but at higher Li contents (≥0.4) accessed by this route, phase separation occurs with the indication that Li occupies another site.

Description

Publication status: Published

Keywords

34 Chemical Sciences, 3406 Physical Chemistry

Journal Title

Inorg Chem

Conference Name

Journal ISSN

0020-1669
1520-510X

Volume Title

63

Publisher

American Chemical Society (ACS)
Sponsorship
Leverhulme Trust (RPG-2018-377)
Engineering and Physical Sciences Research Council (EP/L000202)
Engineering and Physical Sciences Research Council (EP/P020194/1)
Engineering and Physical Sciences Research Council (EP/R029431)
Engineering and Physical Sciences Research Council (EP/R042594/1)
Engineering and Physical Sciences Research Council (EP/T022213/1)
Engineering and Physical Sciences Research Council (EP/T027991/1)