Magnetic domains in rare-earth cobalt permanent magnets

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5599178

Hadjipanayis, G C; Hazelton, R C; Lawless, K R; Horton, L S

The microstructure of two commercial 2:17 precipitation hardened rare-earth magnets has been examined and compared with the magnetic properties. Transmission electron microscope studies on Sm(Co,Fe,Cu,Hf)/sub 7/ /sub 25/, Hicorex 99C show a fine cellular microstructure with 2:17 rhombohedral cells surrounded by coherent 1:5 hexagonal cell boundaries. In Sm(Co,Fe,Cu,Zr)/sub 7/ /sub 22/, TDK REC-26 the cells are much coarser and 1:3 phase thin lamellae are superimposed on the cellular structure. X-ray energy dispersive analysis shows a higher Cu content in the cell boundaries. Lorentz electron microscopy shows wavy domain walls in both cases indicating that the domain walls are pinned at the cell boundaries. The higher Cu content of the cell boundaries dilutes the magnetic properties of the SmCo/sub 5/, phase and produces a large domain wall energy gradient across the cell boundary leading to the observed high coercivities.

• Research Organization: Kollmorgen Corp., Radford, VA (USA); Virginia Univ., Charlottesville (USA); Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5599178
• Report Number(s): CONF-820727-6; ON: DE83015529
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
COBALT ALLOYS
COERCIVE FORCE
COPPER ADDITIONS
COPPER ALLOYS
CRYSTAL STRUCTURE
DOMAIN STRUCTURE
IRON ADDITIONS
IRON ALLOYS
MAGNETS
MICROSTRUCTURE
PERMANENT MAGNETS
RARE EARTH ALLOYS
SAMARIUM ALLOYS
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS