Jm. Yang et al., OBSERVATION OF MICROSTRUCTURES AND MAGNETIC DOMAINS OF SM-CO BASED PERMANENT-MAGNETS BY HIGH-VOLTAGE ELECTRON-MICROSCOPY, Materials transactions, JIM, 38(4), 1997, pp. 363-366
Microstructures and magnetic domains of precipitation hardened Sm(Co0.
653Fe0.257Cu0.066Zr0.024)(7.3) permanent magnets were investigated usi
ng a high-voltage electron microscope. The cellular microstructures co
ntrolled by step aging were clearly observed on atomic scale by high-v
oltage HREM. It was found that the cell interior phases of as-sintered
magnets contained microtwins but those of step aged magnets contained
the Z phase on the basal plane with disappearance of the twins. Also,
Lorentz electron microscope images showed that the domain wall pinnin
g at the cell boundary phases of the SmCo5 structure was increased by
the step aging. Furthermore, the intensity distributions of Lorentz el
ectron microscope images obtained by imaging plates were compared with
the calculated intensity distribution, and the domain wall width was
evaluated to be 10 nm.