Electrical transport properties of Yb8-xYxV2O17 (x = 0; 2; 8)

Abstract

The UV-vis-NIR and electrical properties of Yb8􀀀xYxV2O17 for x = 0, 2, and 8 were investigated. The band energy gap of 2.6 eV determined for Yb6Y2V2O17 (x = 2) and comparable for the remaining compounds with x = 0 and 8 is characteristic for insulators. Low electrical conductivity with a characteristic minimum shifting to higher temperatures from 322, via 360 to 370 K in the sequence x = 0, 2 and 8, which decreases with increasing content of ytterbium was observed. Temperature dependence of thermoelectric power showed n􀀀p transition at 410 and 467 K for x = 0 and 2, respectively, and n-type conductivity for x = 8, indicating mainly n-type electrical conductivity. A breakdown voltage of 26 V/mm is mainly observed for the I􀀀V characteristics at 400 K and showing a varistor-like behawior[…]