Synthesis of hexagonal nanophases in the La2O3 – MO3 (M = Mo, W) systems

Authors

Baldin Egor¹ , Lyskov Nikolay² , Vorobieva Galina¹ , Kolbanev Igor¹ , Karyagina Olga³ , Stolbov Dmitry⁴ , Voronkova Valentina⁴ , Shlyakhtina Anna¹

1. N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences
2. Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS
3. Emanuel Institute of Biochemical Physics RAS
4. Lomonosov Moscow State University

Conference / event

8th Asian Symposium on Advanced Materials ASAM-8, July 2023 (Novosibirsk, Russian Federation)

Poster summary

We present a study of nanophases in the La2O3-MO3 (M = Mo, W) systems, which are known to contain a variety of good oxygen-ion and proton conductors. Mechanically activated La2O3+MO3 (M = Mo, W) mixtures have been characterized by DSC and XRD with Rietveld refinement, SEM, and impedance spectroscopy in dry and wet atmospheres. In both systems, the formation of hexagonal La18M10O57 (M = Mo, W) nanophases is observed, with exothermic peaks in the DSC curve in the range ~480–520 °C for La18Mo10O57 and ~ 685 -760 ºС for La18W10O57. At higher temperatures we observe irreversible reconstructive phase transitions from hexagonal La18Mo10O57 to tetragonal γ- La2MoO6 and from hexagonal La18W10O57 to orthorhombic β-La2WO6. We compare the temperature dependence of the conductivity of nano- and microcrystalline hexagonal La18M10O57 (M = Mo, W) phases and high temperature phases with different densities.

Keywords

Nanophase, Lanthanum molybdate, Lanthanum tungstate, Mechanoactivation, Phase formation

Research areas

Chemistry, Material Sciences

References

No data provided

Funding

1. Russian Foundation for Basic Research (No. 20-03-00399)
2. Ministry of Education and Science (No. 122040500071-0, 122040500068-0))
3. HSE Scientific and Educational Group (No. 23-00-001)

Supplemental files

No data provided

Additional information

Competing interests

No competing interests were disclosed.

Data availability statement

The datasets generated during and / or analyzed during the current study are available from the corresponding author on reasonable request.

Creative Commons license

Copyright © 2023 Egor et al. This is an open access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.