Accession Number : ADA268368


Title :   Spectral Origins of Giant Faraday Rotation and Ellipticity in Bi- Substituted Magnetic Garnets


Descriptive Note : Meeting speech,


Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB


Personal Author(s) : Dionne, Gerald F ; Allen, Gary A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a268368.pdf


Report Date : 15 May 1993


Pagination or Media Count : 5


Abstract : Electrical permittivity theory has been applied to the interpretation of data describing the anomalously high Faraday rotation and ellipticity in the Y(3-x)Bi(x)Fe5O12 ferrimagnetic system. By the use of exact forms of the basic phenomenological equations for the off-diagonal tensor element epsilon (1sub)= epsilon'(1sub)+ epsilon (1sub), the measured Bi(3+) influence on the separate component epsilon'1 and epsilon (1sub) spectra from 1 to 5 eV has been closely fitted to theory by the superposition of three Fe(3+) (diamagnetic) electric dipole transitions occurring at 2.6, 3.15, and 3.9 eV, respectively. The strong transition at 3.15 eV that is believed to originate from Fe-06 molecular complexes of the octahedral sublattice may also have a smaller companion peak in the vicinity of 5 eV. Transition bandwidths and excited-state splittings determined from the matching of theory to experiment both indicate that strong Bi covalent interactions exist with the Fe-06 and Fe-04 complexes. These results also confirm that the enhanced magneto-optical effects in the longer-wavelength region (Lambda approx. 1 micrometer) are dominated by the tail of the epsilon'(1sub) diamagnetic peak at 3.15 eV.


Descriptors :   *MAGNETIC PROPERTIES , *MAGNETOOPTICS , *IRON , *FARADAY EFFECT , *OXIDES , *ROTATION , *YTTRIUM , *BISMUTH , *GARNET , REPRINTS , COVALENT BONDS , DIPOLES , TRANSITIONS , BANDWIDTH , SELECTION RULES(PHYSICS) , MOLECULAR COMPLEXES , ELLIPSES , MATCHING , TENSORS , MOLECULAR STRUCTURE , SPECTRA , REGIONS , EPITAXIAL GROWTH , INTERACTIONS , EXCITATION


Subject Categories : Inorganic Chemistry
      Crystallography
      Electricity and Magnetism
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE