Accession Number : AD0637672

Title :   EFFECTS OF LOCAL ATOMIC ORDER ON THE MAGNETIC PROPERTIES OF AU-25 AT.% FE.

Descriptive Note : Technical rept.

Corporate Author : MINNESOTA UNIV MINNEAPOLIS INST OF TECH

Personal Author(s) : Sundahl,R. ; Sivertsen,J. ; Chen,T.

Report Date : OCT 1964

Pagination or Media Count : 5

Abstract : In a study of the effect of local atomic order on the physical properties of metallic solid solutions, the authors have measured changes in magnetic properties of a Au-25 at. % Fe alloy with heat treatment. Measurements of orgma were made as a function of H between 9.0 and 18.5 kOe and T between 78 and +320K. The Curie temperatures were determined from plots of H/orgma vs sigma squared and the magnetic moment of 0K from an extrapolation of a plot of orgma(18.5 k)e) vs T to the (3/2) power. The local-order parameters were determined for the two states from x-ray diffuse scattering measurements. Application of the cluster-variation method to the calculation of the Curie temperatures from the order parameters gives quantitative agreement with the experimental measurements, while the use of a Curie-Weiss model gives values which are higher than experiment. The magnetic moments on the iron atoms are found to be higher than for pure iron and to increase with the change in order. (Author)

Descriptors :   (*GOLD ALLOYS, MAGNETIC PROPERTIES), IRON ALLOYS, SOLID SOLUTIONS, ATOMIC ENERGY LEVELS, MEASUREMENT, MAGNETIC MOMENTS

Subject Categories : Metallurgy and Metallography
      Electricity and Magnetism
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE