1998/08/31 by A. I. Smirnov, M. N. Popova, М. Н. Попова +11 · 2 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Transition Metal Oxide Nanomaterials #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.59.14546
3 PS-figures, LATEX-text, new experimental data added, typos corrected
arxiv created 1998/10/27 · openalex publication_date 1999/06/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We found anomalies in the temperature dependence of the dielectric and magnetic susceptibility of NaV2O5 in the microwave and far-infrared frequency ranges. The anomalies occur at the phase transition temperature Tc, at which the spin gap opens. The real parts of the dielectric constants \ensuremathεa and \ensuremathεc decrease below Tc, while \ensuremathεb remains constant. The change in \ensuremathεa is proportional to the square of the ordering parameter below Tc. The dielectric anomalies found indicate a redistribution of charges at the phase transition. The character of the dielectric constant anomalies is of the antiferroelectric type, which is in agreement with the models assuming the zigzag charge ordering in the ab plane below Tc. The anomaly of the microwave magnetic losses is probably related to the coupling between the spin and charge degrees of freedom in vanadium ladders.