Microstructure and magnetic domain structure of boron - enriched Nd 2 ( FeCo ) 14 B melt - spun ribbons

نویسندگان

  • B. Lu
  • M. Q. Huang
  • Q. Chen
  • B. M. Ma
  • D. E. Laughlin
چکیده

Heat treated melt-spun ribbons of (Nd La) Fe Co Nb B have been studied systematically by supercon-ducting quantum interference device (SQUID) magnetometry, conventional transmission electron microscopy (CTEM) and Lorentz transmission electron microscopy (LTEM). The sample's microstructure grew from an amorphous state through a partially crystallized state at 6503C, and "nally to a fully crystallized state at 7503C. Excessive grain growth producing grains from 38 to 68 nm in diameter was observed when the ribbon was annealed at 8503C. Soft magnetic phases such as Fe B and-Fe precipitated at the grain boundaries. These intergranular phases are exchange coupled with the hard phase causing a decrease of H. Exchange-coupling dominant and dipolar-coupling dominant regions co-exist inside the sample. In the latter regions, snake-shaped interactive domains are frequently observed. 1999 Elsevier Science B.V. All rights reserved.

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تاریخ انتشار 1998