Accession Number : AD0709354

Title :   CATION DISTRIBUTION IN ALUMINUM-SUBSTITUTED YTTRIUM IRON GARNETS BY MOSSBAUER EFFECT SPECTROSCOPY.

Descriptive Note : Physical sciences research papers,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Czerlinsky,Ernst R. ; MacMillan,Raymond A.

Report Date : APR 1970

Pagination or Media Count : 22

Abstract : As part of a continuing search for magnetic materials with improved properties and broader applicability in microwave devices, recoil-free nuclear resonance absorption was determined on eleven different compositions of Y(3)Al(t)Fe(5-t)O(12) powder specimens with 0.39 = or < to = or < 4 above their Curie temperatures. The quadrupole splittings of the Fe57 nuclei in the garnet structure caused two absorption doublets for each composition. From the intensities of the lines, the distribution of Fe(3+) and Al(3+) on the tetrahedral and octahedral sites with regard to the composition was obtained. Some of the powders had been subjected to the identical and controlled heat treatment to establish their cation equilibrium at the same temperature. With both the cation distribution and the equilibrium temperature defined, the stabilization energy could be determined for each compound. This quantity is a measure for the 'site preference,' in our particular case of Al(3+) in AlYIG materials. The results on the distribution are compared with earlier work on AlYIG, GaYIG and AlYGaG. The electric field gradients resulting from the position of the doublet lines are compared with other investigations on the same compounds. (Author)

Descriptors :   (*MICROWAVE EQUIPMENT, MAGNETIC MATERIALS), (*GARNET, *MOSSBAUER EFFECT), ALUMINUM COMPOUNDS, YTTRIUM COMPOUNDS, FERRATES, CRYSTAL STRUCTURE

Subject Categories : Inorganic Chemistry
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE