Structure, conductivity and magnetism of orthorhombic and fluorite polymorphs in MoO3–Ln2O3 (Ln = Gd, Dy, Ho) systems

Simple item page
dc.contributor.authorShlyakhtina, AVen_AU
dc.contributor.authorAvdeev, Men_AU
dc.contributor.authorLyskov, NVen_AU
dc.contributor.authorAbrantes, JCCen_AU
dc.contributor.authorGomes, EDen_AU
dc.contributor.authorDenisova, KNen_AU
dc.contributor.authorKolbanev, IVen_AU
dc.contributor.authorChernyak, SAen_AU
dc.contributor.authorVolkova, OSen_AU
dc.contributor.authorVasiliev, ANen_AU
dc.date.accessioned2021-07-28T02:08:08Zen_AU
dc.date.available2021-07-28T02:08:08Zen_AU
dc.date.issued2020-01-24en_AU
dc.date.statistics2021-07-10en_AU
dc.description.abstractPhase-pure orthorhombic compositions at a Ln/Mo ratio ∼ 5.2–5.7 (Ln = Gd, Dy, Ho) have been obtained for the first time by prolonged (40–160 h) heat treatment of mechanically activated 5Ln2O3 + 2MoO3 (Ln = Gd, Dy, Ho) oxide mixtures at 1200 °C. Although the starting Ln[thin space (1/6-em)]:[thin space (1/6-em)]Mo ratio was 5[thin space (1/6-em)]:[thin space (1/6-em)]1 (Ln10Mo2O21 (Ln = Dy, Ho)), it changed slightly in the final product due to the volatility of molybdenum oxide at 1200 °C (40–160 h) (ICP-MS analysis). Brief high-temperature firing (1600 °C, 3 h) of 5Ln2O3 + 2MoO3 (Ln = Gd, Dy, Ho) oxide mixtures leads to the formation of phase-pure fluorites with compositions close to Ln10Mo2O21 (Ln = Gd, Dy, Ho). Gd10Mo2O21 molybdate seems to undergo an order–disorder (orthorhombic–fluorite) phase transition in the range of 1200–1600 °C. For the first time, using the neutron diffraction method, it was shown that low-temperature phases with a Ln/Mo ratio ∼ 5.2–5.7 (Ln = Gd, Dy, Ho) have an orthorhombic structure rather than a tetragonal structure. Proton contribution to the total conductivity of Ln10Mo2O21 (Ln = Gd, Dy, Ho) fluorites and gadolinium and dysprosium orthorhombic phases in a wet atmosphere was observed for the first time. In both orthorhombic and fluorite phases, the total conductivity in wet air decreases with decreasing lanthanide ionic radii. In a wide temperature range, the compounds under study exhibit paramagnetic behaviour. However, the orthorhombic phases of Dy and Ho compounds reach the antiferromagnetic state at 2.4 K and 2.6 K, respectively. © The Royal Society of Chemistry 2020en_AU
dc.identifier.citationShlyakhtina, A. V., Avdeev, M., Lyskov, N. V., Abrantes, J. C. C., Gomes, E., Denisova, K. N., Kolbanev, I. V., Chernyak, S. A., Volkova, O. S., & Vasiliev, A. N. (2020). Structure, conductivity and magnetism of orthorhombic and fluorite polymorphs in MoO3–Ln2O3 (Ln = Gd, Dy, Ho) systems. Dalton Transactions, 49(9), 2833-2842. doi:10.1039/C9DT04724Gen_AU
dc.identifier.issn1477-9234en_AU
dc.identifier.issue9en_AU
dc.identifier.journaltitleDalton Transactionsen_AU
dc.identifier.pagination2833-2842en_AU
dc.identifier.urihttps://doi.org/10.1039/C9DT04724Gen_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/11134en_AU
dc.identifier.volume49en_AU
dc.language.isoenen_AU
dc.publisherRoyal Society of Chemistryen_AU
dc.subjectOrthorhombic latticesen_AU
dc.subjectHeat treatmentsen_AU
dc.subjectOxidesen_AU
dc.subjectMolybdenumen_AU
dc.subjectFluoriteen_AU
dc.subjectPhase transformationsen_AU
dc.subjectNeutron diffractionen_AU
dc.subjectGadoliniumen_AU
dc.subjectDysprosiumen_AU
dc.subjectRare earthsen_AU
dc.subjectAntiferromagnetismen_AU
dc.titleStructure, conductivity and magnetism of orthorhombic and fluorite polymorphs in MoO3–Ln2O3 (Ln = Gd, Dy, Ho) systemsen_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles