Size dependent electronic structure of LiFePO4 probed using X-ray absorption and Mossbauer spectroscopy

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10456486" target="_blank" >RIV/00216208:11320/22:10456486 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Td2va0CjG_" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Td2va0CjG_</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d2cp00411a" target="_blank" >10.1039/d2cp00411a</a>

Result language

angličtina

Original language name

Size dependent electronic structure of LiFePO4 probed using X-ray absorption and Mossbauer spectroscopy

Original language description

We present the combined Mossbauer and X-ray absorption spectroscopy investigation of the electronic structure and local site symmetry of Fe in olivine structured LiFePO4 (LFP) with crystallite size (CS). The lattice parameters are found to contract with a decrease in CS, monotonously, whereas the electronic structural parameters exhibit two different regions with a threshold anomaly of around approximate to 30 nm. Fe-57 Mossbauer studies reveal the coexistence of Fe2+ and Fe3+ sites and their relative concentrations are mainly determined by CS, which provides a comprehensive insight into the electronic structure of LFP at the mesoscopic level. The soft X-ray absorption unequivocally unravels the valence states of Fe 3d electrons in proximity to the Fermi level, which are prone to the local lattice distortion. The obtained spectra fingerprint the effect of CS supplying rich information on valency, lithium-ion vacancy concentration, covalency and crystal field. By comparing the spectra with the results of charge-transfer multiplet calculations, which include the full-atomic multiplet theory, we have found that the local symmetry of Fe ions is well described by the D-4h point group with intermixing between e(g) and t(2g) orbitals. The unique structural and electronic properties of LFP are closely interlinked with changes in the bonding character, which shows the strong dependency on CS. The evolution of 3d states is in overall agreement with the local lattice distortion and provides the origin of the size effects on the electronic structure of olivine phosphate and other transition metal ion-containing materials.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

<a href="/en/project/LM2018116" target="_blank" >LM2018116: Surface Physics Laboratory - Materials Science Beamline</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

24

Issue of the periodical within the volume

16

Country of publishing house

GB - UNITED KINGDOM

Number of pages

12

Pages from-to

9695-9706

UT code for WoS article

000781498400001

EID of the result in the Scopus database

2-s2.0-85128740963