THE PREPARATION AND PROPERTIES OF SOME VANADIUM SPINELS
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 25, 1962
- Accession Number
- AD0282542
Entities
People
- D.b. Rogers
Organizations
- Massachusetts Institute of Technology