Accession Number : AD0670560

Title :   ELECTRICAL PROPERTIES OF VANADIUM PENTOXIDE.

Descriptive Note : Technical rept.,

Corporate Author : OREGON STATE UNIV CORVALLIS

Personal Author(s) : McCulloch,John C.

Report Date : 27 MAY 1968

Pagination or Media Count : 53

Abstract : The dc conductivity of single crystals of vanadium pentoxide was measured in the three crystallographic directions. The temperature range examined was -165C to + 25C. The activation energy of the conduction process was isotropic and found to be .56 ev. The conductivity was anisotropic. Measurements of the Hall effect were attempted with a dc and ac apparatus, but the signal was too low to be observed. However, an upper limit of 71 cu cm/coulomb for the Hall coefficient was calculated, and the upper limit computed for the mobility was .4 sq cm/volt sec. A model is proposed for the conduction mechanism. It suggests that the electrical conduction is a two-step process. The electron is ionized from a V(4+)-oxygen-vacancy center and then moves through the lattice via polaron movement. This model accounts for the isotropy of the activation energy and also the anisotropy of the conductivity. (Author)

Descriptors :   (*ELECTRODES, OXIDES), (*VANADIUM COMPOUNDS, ELECTRICAL PROPERTIES), SINGLE CRYSTALS, ELECTRICAL CONDUCTIVITY, DIRECT CURRENT, SYMMETRY(CRYSTALLOGRAPHY), HEAT OF ACTIVATION, HALL EFFECT, IONIZATION, TRANSPORT PROPERTIES

Subject Categories : Physical Chemistry
      Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE