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Title: {open_quotes}Exchange-spring{close_quotes} Nd-Fe-B alloys: Investigations into reversal mechanisms and their temperature dependence

Conference ·
OSTI ID:385597
;  [1];  [2]
  1. Brookhaven National Labs., Upton, NY (United States)
  2. Magnequench International, (MQI), Inc., Anderson, IN (United States)

In order to investigate factors affecting coercivity a series of two-phase Nd{sub 2}Fe{sub 14}B-based nanocomposite alloys with different excess iron concentrations were produced by melt-spinning methods. The constituent grain size was estimated by diffraction methods to be in the range of 150 {Angstrom} - 500 {Angstrom}, and room-temperature demagnetization curves verify that the alloys studied exhibit a modest remanence enhancement. Isothermal remanence magnetization (IRM) and dc-demagnetization (DCD) measurements performed at temperatures in the range 275 K {le} T {le} 350 K illustrate that the coercivity and irreversible magnetization develops in a bimodal, incoherent manner from a demagnetized state but upon demagnetization from a saturated state the system evinces collective, exchange-coupled behavior as illustrated by the reversible magnetization M{sub rev}. The temperature dependencies and values of the irreversible susceptibility X{sub irr} (DCD) suggest that a moderating phase with a magnetic anisotropy intermediate to the two constituent main phases may be present in the alloys.

Research Organization:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC02-76CH00016
OSTI ID:
385597
Report Number(s):
BNL-63415; CONF-961141-2; ON: DE97000140; TRN: 96:005851
Resource Relation:
Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: 1996
Country of Publication:
United States
Language:
English