This work investigates the lithium doping effect on the structural and thermal behavior of (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O high entropy oxide (HEO) obtained by co-precipitation. The powders are characterized by differential thermal and thermogravimetric analyses (DTA-TG), mass spectroscopy, dila tometry, X-ray diffraction (XRD), magic angle spinning nuclear magnetic resonance (MAS NMR), Raman spectroscopy, X-ray photoelectron spectra (XPS) and electron spin resonance (ESR). The results point out that Co3+ ions (within a spinel phase) are reduced to Co2+ before the formation of the high entropy oxide in the absence of Li. Conversely, no reduction is observed in the case of Li-doping, thus indicating the presence of Co3+ within the high entropy rock salt lattice. At high temperature (> 1050–1150 °C), the HEO phase loses oxygen changing the charge compensation mechanism for Li incorporation (mostly based on the presence of 3 + cations and oxygen vacancies at low and high temperatures, respectively). Moreover, it is found that lithium lies in two well-distinct chemical environments in HEO, which cannot be completely explained by assuming a random organization of the high entropy phase. This suggests the existence of some short-range order and possible M3+-Li+ pairs.

A structural and thermal investigation of Li-doped high entropy (Mg, Co, Ni, Cu, Zn)O obtained by co-precipitation / Spiridigliozzi, L.; Dell'Agli, G.; Callone, E.; Dirè, S.; Campostrini, R.; Bettotti, P.; Bortolotti, M.; Speranza, G.; Sglavo, V. M.; Biesuz, M.. - In: JOURNAL OF ALLOYS AND COMPOUNDS. - ISSN 0925-8388. - 927:(2022), pp. 16693301-16693311. [10.1016/j.jallcom.2022.166933]

A structural and thermal investigation of Li-doped high entropy (Mg, Co, Ni, Cu, Zn)O obtained by co-precipitation

Callone E.;Dirè S.;Campostrini R.;Bettotti P.;Bortolotti M.;Sglavo V. M.;Biesuz M.
2022-01-01

Abstract

This work investigates the lithium doping effect on the structural and thermal behavior of (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)O high entropy oxide (HEO) obtained by co-precipitation. The powders are characterized by differential thermal and thermogravimetric analyses (DTA-TG), mass spectroscopy, dila tometry, X-ray diffraction (XRD), magic angle spinning nuclear magnetic resonance (MAS NMR), Raman spectroscopy, X-ray photoelectron spectra (XPS) and electron spin resonance (ESR). The results point out that Co3+ ions (within a spinel phase) are reduced to Co2+ before the formation of the high entropy oxide in the absence of Li. Conversely, no reduction is observed in the case of Li-doping, thus indicating the presence of Co3+ within the high entropy rock salt lattice. At high temperature (> 1050–1150 °C), the HEO phase loses oxygen changing the charge compensation mechanism for Li incorporation (mostly based on the presence of 3 + cations and oxygen vacancies at low and high temperatures, respectively). Moreover, it is found that lithium lies in two well-distinct chemical environments in HEO, which cannot be completely explained by assuming a random organization of the high entropy phase. This suggests the existence of some short-range order and possible M3+-Li+ pairs.
2022
Spiridigliozzi, L.; Dell'Agli, G.; Callone, E.; Dirè, S.; Campostrini, R.; Bettotti, P.; Bortolotti, M.; Speranza, G.; Sglavo, V. M.; Biesuz, M.
A structural and thermal investigation of Li-doped high entropy (Mg, Co, Ni, Cu, Zn)O obtained by co-precipitation / Spiridigliozzi, L.; Dell'Agli, G.; Callone, E.; Dirè, S.; Campostrini, R.; Bettotti, P.; Bortolotti, M.; Speranza, G.; Sglavo, V. M.; Biesuz, M.. - In: JOURNAL OF ALLOYS AND COMPOUNDS. - ISSN 0925-8388. - 927:(2022), pp. 16693301-16693311. [10.1016/j.jallcom.2022.166933]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/355143
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