Permeability, magnetomechanical coupling and magnetostriction in grain-oriented rare earth--iron alloys

Conference · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.1063/1.327234· OSTI ID:6490295

Savage, H T; Abbundi, R; Clark, A E; McMasters, O D

Grain-oriented samples of highly magnetostrictive rare earth--iron compounds have successfully been prepared. These samples possess lower inhomogeneous strains than found in the random polycrystalline RFe/sub 2/ compounds, resulting in much higher values of relative permeability (..mu../sub r/) and magnetomechanical coupling (K/sub 33/). A partiallly oriented Tb /sub 20/Dy /sub 22/Ho /sub 58/Fe/sub 1/ /sub 95/ sample was prepared using a pyrolytic Bridgman type boron nitride crucible. At a bias field of 100 Oe k/sub 33/ = .73, which is considerably larger than found in the random polycrystal of the same composition. A relative permeability of 36 occurs in this same sample when a low ac drive of 1.6 Oe rms is used. A second fabrication method using a horizontal zone technique with a supporting cold finger was employed to grow the ternary Tb /sub 27/Dy /sub 73/Fe/sub 1/ /sub 98/. The low ac drive values of k/sub 33/ and ..mu../sub r/ were .74 and 19 respectively. The permeability at low bias was found to possess a sharp ac drive dependence. Near zero bias, when the drive was changed from 1.6 Oe rms to 13 Oe rms, ..mu../sub r/ in the quaternary increased from 36 to 98. In the ternary the values of ..mu../sub r/ near zero bias increased from 19 to 61. Magnetostriction measurements on both samples show a significant increase in dlambda/dH and lambda/sub s/ over the random polycrystals.

• Research Organization: Naval Surface Weapons Center, Silver Spring, MD (USA); Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6490295
• Report Number(s): IS-M-174; CONF-781114-11
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
DYSPROSIUM ALLOYS
FABRICATION
GRAIN ORIENTATION
HOLMIUM ALLOYS
IRON ALLOYS
LAVES PHASES
MAGNETIC PROPERTIES
MAGNETOSTRICTION
MICROSTRUCTURE
ORIENTATION
PERMEABILITY
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRECIPITATION
RARE EARTH ALLOYS
SEPARATION PROCESSES
TERBIUM ALLOYS
WIDMANSTAETTEN STRUCTURE