English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution

MPS-Authors
/persons/resource/persons126756

Mikhailova,  D.
Daria Mikhailova, Physics of Correlated Matter, Max Planck Institute for Chemical Physics of Solids, Max Planck Society;

/persons/resource/persons130020

Utsumi,  Y.
Physics of Correlated Matter, Max Planck Institute for Chemical Physics of Solids, Max Planck Society;

/persons/resource/persons126835

Schmidt,  M.
Marcus Schmidt, Chemical Metal Science, Max Planck Institute for Chemical Physics of Solids, Max Planck Society;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Mikhailova, D., Kuratieva, N. N., Utsumi, Y., Tsirlin, A. A., Abakumov, A. M., Schmidt, M., et al. (2017). Composition-dependent charge transfer and phase separation in the V1-xRexO2 solid solution. Dalton Transactions, 46(5), 1606-1617. doi:10.1039/c6dt04389e.


Cite as: http://hdl.handle.net/11858/00-001M-0000-002D-0A2A-C
Abstract
The substitution of vanadium in vanadium dioxide VO2 influences the critical temperatures of structural and metal-to-insulator transitions in different ways depending on the valence of the dopant. Rhenium adopts valence states between + 4 and + 7 in an octahedral oxygen surrounding and is particularly interesting in this context. Structural investigation of V1-xRexO2 solid solutions (0.01 <= x <= 0.30) between 80 and 1200 K using synchrotron X-ray powder diffraction revealed only two polymorphs that resemble VO2: the low-temperature monoclinic MoO2-type form (space group P2(1)/c), and the tetragonal rutile-like form (space group P4(2)/mnm). However, for compositions with 0.03 < x <= 0.15 a phase separation in the solid solution was observed below 1000 K upon cooling down from 1200 K, giving rise to two isostructural phases with slightly different lattice parameters. This is reflected in the appearance of two metal-toinsulator transition temperatures detected by magnetization and specific heat measurements. Comprehensive X-ray photoelectron spectroscopy studies showed that an increased amount of Re leads to a change in the Re valence state from solely Re6+ at a low doping level (<= 3 at% Re) via mixed-valence states Re4+/Re6+ for at least 0.03 < x <= 0.10, up to nearly pure Re4+ in V0.70Re0.30O2. Thus, compositions V1-xRexO2 with only one valence state of Re in the material (Re6+ or Re4+) can be obtained as a single phase, while intermediate compositions are subjected to a phase separation, presumably due to different valence states of Re.