Systematics in the metal-insulator transition temperatures in vanadium oxides

B. Fisher; J. Genossar; G. M. Reisner

doi:10.1016/j.ssc.2015.10.015

paper

Systematics in the metal-insulator transition temperatures in vanadium oxides

arXiv:1510.08286 · doi:10.1016/j.ssc.2015.10.015

Abstract

Nine of the known vanadium oxides, VO $_{2 - 1/ n}$ (n - a positive or negative integer) with n=2 - 6, 8, 9, $\infty$ and -6, undergo metal-insulator transitions accompanied by structural transitions, at various temperatures T $_{M I T}$ (V $_{7}$ O $_{13}$ is metallic above T=0). Among the persistent efforts to determine the driving force(s) of these transitions, electron-electron (Mott-like) and electron-phonon (Peierls-like) interactions, there were several attempts to find systematics in T $_{M I T}$ as function of n. Here we present an unexpectedly simple and illuminating systematics that holds for positive n: if T $_{M I T}$ is the absolute value of the difference between T $_{M}$ (n) and T $_{P}$ (n), which represent the contributions of electron-electron and electron-phonon interactions, respectively, all data points of T $_{M}$ -T $_{P}$ versus 1/n lie on, or close to, two simple straight lines; one is T $_{M}$ -T $_{P}$ = T $_{\infty}$ (7/n-1) for V $_{3}$ O $_{5}$ , V $_{4}$ O $_{7}$ , V $_{5}$ O $_{9}$ , V $_{7}$ O $_{13}$ , V $_{8}$ O $_{15}$ , V $_{9}$ O $_{17}$ and VO $_{2}$ and the other is T $_{M}$ -T $_{P}$ = T $_{\infty}$ (3/n-1) for V $_{2}$ O $_{3}$ , V $_{6}$ O $_{11}$ and VO $_{2}$ .

Accepted for publication in Solid State Communication

References in corpus (1)

VO: A Strongly Correlated Metal Close to a Mott- Hubbard Transition