Mossbauer Study of Magnetic States of KFeF3 and Implications for RbFeF3.
Abstract
Mossbauer absorption spectra of 57Fe in an unstrained (100) single crystal platelet of KFeF3 have been measured between 297 and 4.2K. The transition to the trigonal antiferromagnetic state occurred at T9N) = 112.5 plus or minus 0.5K. Analysis of the data in the antiferromagnetic phase indicates the spin alignment is parallel to the <111> distortion. The temperature dependence of H(hf) and delta E(Q) in this phase is compared with predictions of self-consistent molecular field theory calculations. Only fair agreement is found with the magnetically induced EFG model, which describes the Fe(2+) ion by a Hamiltonian incorporating free ion terms, a cubic crystal field, and an exchange interaction. A substantially better fit is obtained with a second model. Application of this second model to the tetragonal antiferromagnetic state of RbFeF3 indicates the spins align parallel to a <100> direction rather than the <111> direction predicted previously by use of the magnetically induced EFG model. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1973
- Accession Number
- AD0764635
Entities
People
- Gerald R. Davidson
- H. J. Guggenheim
- M. Eibschutz
Organizations
- University of Pennsylvania