A STUDY OF THE LOW TEMPERATURE TRANSITION IN MAGNETITE AND THE INTERNAL FIELDS ACTING ON IRON NUCLEI IN SOME SPINEL FERRITES, USING MOSSBAUER ABSORBTION
Abstract
A study has been made of the internal fields acting on Fe-57 nuclei in some spinel ferrites, with particular reference to the low temperature order-disorder transition in magnetite, using the techniques of Mossbauer absorbtion. For the Fe(+++) ions at both the octahedral and tetrahedral sites in nickel ferrite at 300 K, Gamma Fe2O03 at 85 K and 300 K, and magnetite at 85 K, the effective magnetic field at the Fe-57 nuclei is the same and equal to about 5.1 x 10 to the 5th power oe. In magnetite, the value of H(eff) in the Fe(++) ions is about 4.5 x 10 to the 5th power oe at 85 K. Measurements on magne ite at room temperatures provide a microscopic confirmation of Verwey's hypothesis that above the transition temperature of magnetite there is a fast exchange between the ferrous and ferric ions in the octahedral sites. The average value obtained for the chemical shift (relative to stainless steel) for the Fe(+++) ions in the various cases investigated was about .045 cms/sec; the value for the Fe(++) ions in magnetite at 85 K was about 0.115 cms/sec. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1961
- Accession Number
- AD0258337
Entities
People
- A. Marinov
- R. Bauminger
- S.g. Cohen
Organizations
- Hebrew University of Jerusalem