Accession Number : AD0282542

Title :   THE PREPARATION AND PROPERTIES OF SOME VANADIUM SPINELS

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : ROGERS,D.B.

Report Date : 25 MAY 1962

Pagination or Media Count : 1

Abstract : The purpose of this thesis was to prepare several mixed oxides of spinel structure containing trivalent or tetravalent vanadium as a principal constituent in order to investigate the possible effect of direct cation-cation interactions (via overlap of cation d orbitals) on the properties of the d electrons. To accomplish this aim, numerous preparative techniques were worked out for this class of materials and the following end-member spinels were obtained in a reasonably high degree of purity as established by x-ray diffraction and chemical analysis: MnV2O4, FeV2O4, MgV2O4, ZnV2O4, CoV2O4, Fe2VO4, and Co2VO4. Several of the magnetic, electrical transport, and crystallographic properties of these materials were studied. Most of these properties were not readily interpretable in terms of classical mechanisms, but appeared to provide positive experimental evidence for the presence of relatively strong, direct cation-cation interactions. Conclusions were drawn relating to certain characteristics of this latter mechanism. Some amplification of these conclusions was obtained through an extension of the experimental work to include the following mixed systems: CoV2-xAlxO4 (0 is less than or equal to x less than or equal to 2), Fe1+xV2-xO4 (0 is less than or equal to x less than or equal to 1), and Co1+xV2-xO4 (0 is less than or equal to x less than or equal to 1). The properties of these systems were shown to be qualitatively interpretable in terms of direct interactions. (Author)

Descriptors :   *SPINEL, *VANADIUM COMPOUNDS, CHEMICAL ANALYSIS, CRYSTAL STRUCTURE, ELECTRICAL PROPERTIES, OXIDES, PHYSICAL PROPERTIES, TRANSPORT PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE