skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Compositional clustering in Nd{sub 2}Fe{sub 14}B melt-spun ribbons

Abstract

Elevated-temperature superconducting quantum interference device magnetometry was employed to investigate the detailed phase constitution of nominally glassy stoichiometric Nd{sub 2}Fe{sub 14}B melt-spun ribbons modified with 6 wt % Ti/C and subjected to various degrees of quenching by circumferential wheel speed variations of 40, 35, and 20 m/s. While previous microstructural characterization indicated that these materials were completely amorphous, ac susceptibility and magnetization measurements analyzed within the framework of superparamagnetism indicates that the materials actually contain a concentration of crystalline phase clusters of Nd{sub 2}Fe{sub 14}B and {alpha}-Fe that remained undetected by previous microstructural characterization due to their small size (diameter <5 nm) and inhomogeneous spatial distribution. The Curie temperatures of the glassy component increase with decreasing wheel speed, while the amount of glass varies in a systematic manner from 78 to 91 wt %. The remaining phases in the quenched product are Nd{sub 2}Fe{sub 14}B and {alpha}-Fe. Analysis of the distribution and size of the {alpha}-Fe clusters provides insight into the nucleation and growth process that ultimately produces the crystallized microstructure associated with high energy-product melt-spun Nd{sub 2}Fe{sub 14}B-based magnets. (c) 2000 American Institute of Physics.

Authors:
 [1];  [2];  [2];  [2]
  1. Department of Applied Science, Materials and Chemical Sciences Division, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
  2. Ames Laboratory and Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011 (United States)
Publication Date:
OSTI Identifier:
20216206
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 87; Journal Issue: 9; Other Information: PBD: 1 May 2000; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; NEODYMIUM ALLOYS; IRON ALLOYS; BORON ALLOYS; PERMANENT MAGNETS; SOLIDIFICATION; SPIN-ON COATINGS; MAGNETIZATION; CURIE POINT; AMORPHOUS STATE; EXPERIMENTAL DATA

Citation Formats

Lewis, L. H., Kramer, M. J., Dennis, K. W., and McCallum, R. W. Compositional clustering in Nd{sub 2}Fe{sub 14}B melt-spun ribbons. United States: N. p., 2000. Web. doi:10.1063/1.373142.
Lewis, L. H., Kramer, M. J., Dennis, K. W., & McCallum, R. W. Compositional clustering in Nd{sub 2}Fe{sub 14}B melt-spun ribbons. United States. doi:10.1063/1.373142.
Lewis, L. H., Kramer, M. J., Dennis, K. W., and McCallum, R. W. Mon . "Compositional clustering in Nd{sub 2}Fe{sub 14}B melt-spun ribbons". United States. doi:10.1063/1.373142.
@article{osti_20216206,
title = {Compositional clustering in Nd{sub 2}Fe{sub 14}B melt-spun ribbons},
author = {Lewis, L. H. and Kramer, M. J. and Dennis, K. W. and McCallum, R. W.},
abstractNote = {Elevated-temperature superconducting quantum interference device magnetometry was employed to investigate the detailed phase constitution of nominally glassy stoichiometric Nd{sub 2}Fe{sub 14}B melt-spun ribbons modified with 6 wt % Ti/C and subjected to various degrees of quenching by circumferential wheel speed variations of 40, 35, and 20 m/s. While previous microstructural characterization indicated that these materials were completely amorphous, ac susceptibility and magnetization measurements analyzed within the framework of superparamagnetism indicates that the materials actually contain a concentration of crystalline phase clusters of Nd{sub 2}Fe{sub 14}B and {alpha}-Fe that remained undetected by previous microstructural characterization due to their small size (diameter <5 nm) and inhomogeneous spatial distribution. The Curie temperatures of the glassy component increase with decreasing wheel speed, while the amount of glass varies in a systematic manner from 78 to 91 wt %. The remaining phases in the quenched product are Nd{sub 2}Fe{sub 14}B and {alpha}-Fe. Analysis of the distribution and size of the {alpha}-Fe clusters provides insight into the nucleation and growth process that ultimately produces the crystallized microstructure associated with high energy-product melt-spun Nd{sub 2}Fe{sub 14}B-based magnets. (c) 2000 American Institute of Physics.},
doi = {10.1063/1.373142},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 9,
volume = 87,
place = {United States},
year = {2000},
month = {5}
}