Electrical Conductivity in the Spinel System Co1—xLixV2O4

Publisher Website
Google Scholar
Abstract
The electrical conductivity in the system Co1—xLixV2O4 has been investigated to obtain more information about the physical properties manifested by d electrons in the region of transition from a localized to a collective state. Experimental data for the spinel system Co1—xLix[V2]O4 are presented that indicate R(V) ≈ Rc(V), the V ion separation R is nearly a defined critical separation Rc. All members of the system are semiconductors above 70°K, but are characterized by rather low values for resistivity and activation energy. Substitution of V4+ on the spinel B‐sites effects an initial increase in both these parameters at room temperature, an apparent contradiction to the ``Meyer—Neldel rule,'' which predicts a rapid decrease of activation energy with addition of ``mixed valencies.'' Plots of resistivities as functions of reciprocal temperature indicate that most of the members are characterized by two activation energies: q1 that is dominant at higher temperatures, and q2<q1 that dominates the low‐temperature conductivities.

This publication has 4 references indexed in Scilit: