Coercivity and squareness enhancement in ball-milled hard magnetic-antiferromagnetic composites

Sort, J Nogues, J Surinach, S Munoz, JS Baro, MD Chappel, E Dupont, F Chouteau, G

J. Sort et al., Coercivity and squareness enhancement in ball-milled hard magnetic-antiferromagnetic composites, APPL PHYS L, 79(8), 2001, pp. 1142-1144

26

INGLESE

Article

Apllied Physucs/Condensed Matter/Materiales Science

APPLIED PHYSICS LETTERS

0003-6951 → ACNP

79

8

2001

1142 - 1144

ISI

0003-6951(20010820)79:8<1142:CASEIB>2.0.ZU;2-I

The room-temperature coercivity, H-C, and squareness, M-R/M-S (remanence/sa turation magnetizations), of permanent magnet, SmCo5 powders have been enha nced by ball milling with antiferromagnetic NiO (with Neel temperature, T-N =590 K). This enhancement is observed in the as-milled state. However, when the milling of SmCo5 is carried out with an antiferromagnet with T-N below room temperature (e.g., for CoO, T-N=290 K), the coercivity enhancement is only observed at low temperatures after field cooling through T-N. The fer romagnetic-antiferromagnetic exchange coupling induced either by local heat ing during milling (SmCo5+NiO) or field cooling (SmCo5+CoO) is shown to be the origin of the H-C increase. (C) 2001 American Institute of Physics.