On Electron Transport in ZrB12, ZrB2 and MgB2

V. A. Gasparov; M. P. Kulakov; N. S. Sidorov; I. I. Zver'kova; V. B. Filipov; A. B. Lyashenko; Yu. B. Paderno

doi:10.1134/1.1825116

paper

On Electron Transport in ZrB12, ZrB2 and MgB2

arXiv:cond-mat/0406615 · doi:10.1134/1.1825116

Abstract

We report on measurements of the temperature dependence of resistivity, $ρ (T)$ , for single crystal samples of ZrB $_{12}$ , ZrB $_{2}$ and polycrystalline samples of MgB $_{2}$ . It is shown that cluster compound ZrB $_{12}$ behaves like a simple metal in the normal state, with a typical Bloch -- Grüneisen $ρ (T)$ dependence. However, the resistive Debye temperature, $T_{R} = 300 K$ , is three times smaller than $T_{D}$ obtained from specific heat data. We observe the $T^{2}$ term in $ρ (T)$ of these borides, which could be interpreted as an indication of strong electron-electron interaction. Although the $ρ (T)$ dependence of ZrB $_{12}$ reveals a sharp superconductive transition at $T_{c} = 6.0 K$ , no superconductivity was observed for single crystal samples of ZrB $_{2}$ down to $1.3 K$ .

5 pages, 4 figures