| Issue |
J. Phys. IV France
Volume 12, Number 9, November 2002
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|
|---|---|---|
| Page(s) | 355 - 355 | |
| DOI | https://doi.org/10.1051/jp4:20020436 | |
J. Phys. IV France 12 (2002) Pr9-355
DOI: 10.1051/jp4:20020436
Optical properties of complex oxides: Vanadate ladders and related inorganic nanotubes
J.L. Musfeldt1, A.B. Sushkov1, J. Jegoudez2, A. Revcolevschi2, P. Millet3 and J. Galy31 University of Tennessee, U.S.A.
2 Université Paris-Sud, 91405 Orsay, France
3 CNRS Toulouse, France
Abstract
Optical spectroscopy is a sensitive probe of charge, spin, and lattice degrees of freedom. In
this talk, I will detail our magneto-optical work on alpha'-NaV2O5, a prototypical ladder
material, as well as the new Na2V3O7 nanotubes. Using changes in electronic structure with
temperature and applied magnetic field, we have mapped out the H-T phase diagram of
alpha'-NaV2O5. We find a temperature independent phase boundary at 27 T which persists
above Tc (34 K), a kink in Tc(H) near 27 T, and H
2 behavior of Tc(H) in the high field
phase with an unusually small coupling constant. The energy scale of Tc and the newly
discovered phase boundary at Hc (27 T) are identical. Confinement effects are investigated in
the related nanotubes. Results include a larger gap than in analogous bulk materials as well
as a low-energy rattling mode, which corresponds to the motion of Na+ ions inside the
nanotube.
© EDP Sciences 2002