Spin reorientation in melt-spun neodymium-iron-boron ribbons

Journal Article · Tue Nov 15 00:00:00 EST 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342522· OSTI ID:6746919

Pinkerton, F E

Effects of the spin reorientation in Nd/sub 2/Fe/sub 14/B below T/sub s/ = 135 K on the hard magnetic properties of melt-spun Nd-Fe-B ribbons are reported. As the ribbons are cooled from room temperature, the shape of the second quadrant demagnetization curve is maintained down to 150 K, with an intrinsic coercivity H/sub c//sub i/ which increases steadily from 14 to 24 kOe. As the magnetic structure of Nd/sub 2/ Fe/sub 14/ B changes from easy axis to easy cone below 135 K, however, demagnetization occurs in two steps, with a large decrease in magnetization at low reverse field followed by a second sharp drop at higher field. The size of the initial drop correlates well with the canting angle of the cone and is consistent with having little or no resistance to rotation of the magnetization along the cone. This effect artificially suppresses H/sub c//sub i/ , which decreases to 23 kOe at 5 K. Magnetization reversal from one easy cone to the opposite cone remains a hard process, and its effective coercivity is estimated to be 42 kOe at 5 K. The first quadrant magnetization is much closer to full saturation at low fields due to the improved net alignment of the moments. In thermomagnetic scans this appears as a large increase in magnetization as the sample cools through T/sub s/ at constant field. The observed behavior agrees with that predicted by the known easy cone structure of Nd/sub 2/ Fe/sub 14/ B below T/sub s/ .

• Research Organization: Physics Department, General Motors Research Laboratories, Warren, Michigan 48090-9055
• OSTI ID: 6746919
• Journal Information: J. Appl. Phys.; (United States), Vol. 64:10
• Country of Publication: United States
• Language: English

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