Electrical and magnetic properties of Fe3-zAlzO4 (z<0.06)
Abstract
Electrical resistivity and magnetization measurements have been carried out on synthetic single crystals of Fe3-zAlzO4 in the range 0<=z<0.06. The samples were annealed to achieve the ideal 3:4 ratio of cations to anions. As has been previously reported for nonstoichiometric magnetite and for Zn- and Ti-doped magnetite, there is a change in the nature of the Verwey transition: with increasing z the transformation shifts from first to higher order and then disappears. Saturation magnetization measurements have been used to determine the possible distribution of divalent and trivalent iron and of trivalent aluminum among the tetrahedrally and octahedrally coordinated interstices. Differences in the present findings from those in Zn- and Ti-doped magnetite are pointed out and their implications are discussed.
- Publication:
-
Physical Review B
- Pub Date:
- June 1996
- DOI:
- 10.1103/PhysRevB.53.15113
- Bibcode:
- 1996PhRvB..5315113K
- Keywords:
-
- 72.20.-i;
- 71.30.+h;
- Conductivity phenomena in semiconductors and insulators;
- Metal-insulator transitions and other electronic transitions