Comparative Study of Electrical Conduction and Oxygen Diffusion in the Rhombohedral and Bixbyite Ln6MoO12 (Ln = Er, Tm, Yb) Polymorphs | Sciact - CRIS-system of Boreskov Institute of Catalysis

Comparative Study of Electrical Conduction and Oxygen Diffusion in the Rhombohedral and Bixbyite Ln6MoO12 (Ln = Er, Tm, Yb) Polymorphs Full article

Journal

Inorganic Chemistry
ISSN: 0020-1669 , E-ISSN: 1520-510X

Output data

Year: 2019, Volume: 58, Number: 7, Pages: 4275-4288 Pages count : 14 DOI: 10.1021/acs.inorgchem.8b03397

Tags

FLUORITE-RELATED SUPERSTRUCTURE; RARE-EARTH; TRANSPORT-PROPERTIES; Ln(6-X)MoO(12-δ) Ln; CRYSTAL-CHEMISTRY; PHASE-EQUILIBRIA; SYSTEM; ION; X=0; ELECTROLYTES

Authors

Shlyakhtina Anna V. ¹ , Lyskov Nikolay V. ² , Avdeev Maxim ³ , Goffman Vladimir G. ⁴ , Gorshkov Nikolay V. ⁴ , Knotko Alexander V. ⁵ , Kolbanev Igor V. ¹ , Karyagina Olga K. ⁶ , Maslakov Konstantin I. ⁵ , Shcherbakova Lidia G. ¹ , Sadovskaya Ekaterina M. ^7,8 , Sadykov Vladislav A. ^7,8 , Eremeev Nikita F. ⁷

Affiliations

1	Semenov Institute of Chemical Physics
2	Institute of Problems of Chemical Physics, Russian Academy of Sciences, Academician Semenov ave. 1, Chernogolovka 142432, Moscow Region, Russia
3	Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
4	Yuri Gagarin State Technical University of Saratov, Politechnicheskaya st. 77, Saratov 410054, Russia
5	Lomonosov Moscow State University, Leninskie gory 1, Moscow 119991, Russia
6	Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygina st. 4, Moscow 119991, Russia
7	Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, pr. Akad. Lavrentieva 5, Novosibirsk 630090, Russia
8	Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia

Funding (4)

1	Russian Foundation for Basic Research	16-03-00143 (АААА-А16-116031050045-0)
2	Federal Agency for Scientific Organizations	0082-2014-0011 (АААА-А17-117111600093-8)
3	Russian Foundation for Basic Research	19-03-00358 (АААА-А19-119031290055-2)
4	Russian Science Foundation	16-13-00112

Electrical conduction and oxygen diffusion mobility in the bixbyite (Ia3̅) and rhombohedral (R3̅) polymorphs of the Ln6MoO12−Δ (Ln = Er, Tm, Yb; Δ = δ, δ1, δ2; δ1 > δ2) heavy lanthanide molybdates, belonging to new, previously unexplored classes of potential mixed (ionic–electronic) conductors, have been studied in the range of 200–900 °C. The oxygen self-diffusion coefficient in bixbyite (Ia3̅) Yb6MoO12−δ phase estimated by the temperature-programmed heteroexchange with C18O2 was shown to be much higher than that for rhombohedral (R3̅) RI (with large oxygen deficiency) and (R3̅) RII (with small oxygen deficiency) Ln6MoO12−Δ (Ln = Tm, Yb; Δ = δ1; δ1 > δ2) oxides. According to the activation energy for total conduction in ambient air, 0.99, 0.93, and 1.01 eV in Er6MoO12−δ, Tm6MoO12−δ, and Yb6MoO12−δ bixbyites, respectively, oxygen ion conductivity prevails in the range ∼200–500 °C. Oxygen mobility data for the rhombohedral Ln6MoO12−Δ (Ln = Er, Tm, Yb; Δ = δ1, δ2) phases RI and RII indicate that the oxygen in these phases exhibits mobility at much higher temperatures, such as those above 600–700 °C. Accordingly, below 600–700 °C they have predominantly electronic conductivity. As shown by total conductivity study of Ln6MoO12−δ (Ln = Er, Tm, Yb) bixbyites (Ia3̅) and rhombohedral phases Ln6MoO12−Δ (Ln = Er, Tm, Yb; Δ = δ1, δ2) (R3̅) in dry and wet air, the proton conductivity contribution exists only in Ln6MoO12−δ (Ln = Er, Tm, Yb) bixbyites up to 450–600 °C and decreases with a decreasing of the lanthanide ionic radius. The obtained data on the mobility of oxygen and the presence of proton contribution in bixbyites in the 300–600 °C temperature range make it possible to confirm unequivocally that Ln6MoO12−δ (Ln = Er, Tm, Yb) bixbyites are mixed electron–proton conductors at these temperatures.

Shlyakhtina A.V. , Lyskov N.V. , Avdeev M. , Goffman V.G. , Gorshkov N.V. , Knotko A.V. , Kolbanev I.V. , Karyagina O.K. , Maslakov K.I. , Shcherbakova L.G. , Sadovskaya E.M. , Sadykov V.A. , Eremeev N.F.
Comparative Study of Electrical Conduction and Oxygen Diffusion in the Rhombohedral and Bixbyite Ln6MoO12 (Ln = Er, Tm, Yb) Polymorphs
Inorganic Chemistry. 2019. V.58. N7. P.4275-4288. DOI: 10.1021/acs.inorgchem.8b03397 WOS Scopus РИНЦ AN OpenAlex

Submitted:	Dec 5, 2018
Published online:	Mar 19, 2019
Published print:	Apr 1, 2019

Web of science:	WOS:000463462200031
Scopus:	2-s2.0-85063667686
Elibrary:	38719466
Chemical Abstracts:	2019:501851
OpenAlex:	W2924266316

DB	Citing
Scopus	14
Web of science	14
Elibrary	10
OpenAlex	14