Microstructural and magnetic characterization of rapidly solidified and annealed Pt--Co--B alloys

Journal Article · Fri Nov 15 00:00:00 EST 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.350021· OSTI ID:5060049

Qiu, N; Teubert, J A; Overfelt, R A; Wittig, J E ^[1]

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1. Department of Materials Science and Engineering, Vanderbilt University, Nashville, Tennessee (USA)

Significant increases in intrinsic coercivity ({ital H}{sub ic}) of Pt--Co alloys have been obtained by the addition of boron and the application of rapid solidification processing. After rapid solidification by double anvil splat quenching with subsequent annealing at 650 {degree}C for 30 min, an alloy of Pt{sub 42}Co{sub 45}B{sub 13} (at. %) exhibits an {ital H}{sub ic} as high as 14 kOe. Transmission electron microscopy and Lorentz microscopy were used to interpret the magnetic data. Annealing of the Pt--Co--B influences the {ital L}1{sub 0} superlattice structure and grain size of the matrix, the crystal structure and size of Co-boride precipitate, and the distribution of magnetic domain walls. A microstructural analysis shows that the maximum {ital H}{sub ic} occurs when Co borides, having the Co{sub 3}B structure, are within the single magnetic domain size. The magnetic hardening mechanism in Pt--Co--B is believed to be a combination of inhibited magnetic domain nucleation and difficult reverse magnetic domain growth caused by the interaction of the magnetically anisotropic Co borides with the {ital L}1{sub 0} Pt--Co matrix.

• OSTI ID: 5060049
• Journal Information: Journal of Applied Physics; (United States), Vol. 70:10; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON ALLOYS
DOMAIN STRUCTURE
COBALT ALLOYS
PLATINUM ALLOYS
ANNEALING
HIGH TEMPERATURE
MICROSTRUCTURE
PRECIPITATION
ALLOYS
CRYSTAL STRUCTURE
HEAT TREATMENTS
PLATINUM METAL ALLOYS
SEPARATION PROCESSES
360104* - Metals & Alloys- Physical Properties