The influence of microstructure on magnetic properties of nanocrystalline Fe-Pt-Nb-B permanent magnet ribbons

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3504245· OSTI ID:21476608

Randrianantoandro, N; Greneche, J M ^[1]; Crisan, A D ^[1]; Crisan, O ^[2]; Marcin, J; Kovac, J; Hanko, J; Skorvanek, I ^[3]; Svec, P ^[4]; Chrobak, A ^[5]

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1. Laboratoire de Physique de l'Etat Condense, UMR CNRS 6087, Universite du Maine, 72085 Le Mans cedex 9 (France)
2. National Institute for Materials Physics, P.O. Box MG-7, 76900 Bucharest (Romania)
3. Institute of Experimental Physics, Slovak Academy of Sciences, 043 53 Kosice (Slovakia)
4. Institute of Physics, SAS, Dubravska cesta 9, 84228 Bratislava (Slovakia)
5. August Chelkowski Institute of Physics, University of Silesia, 40-007 Katowice (Poland)

A FePt-based hard-magnetic nanocomposite of exchange spring type was prepared by isothermal annealing of melt-spun Fe{sub 52}Pt{sub 28}Nb{sub 2}B{sub 18} (atomic percent) ribbons. The relationship between microstructure and magnetic properties was investigated by qualitative and quantitative structural analysis based on the x-ray diffraction, transmission electron microscopy, and {sup 57}Fe Moessbauer spectrometry on one hand and the superconducting quantum interference device magnetometry on the other hand. The microstructure consists of L1{sub 0}-FePt hard-magnetic grains (15-45 nm in diameter) dispersed in a soft magnetic medium composed by A1 FePt, Fe{sub 2}B, and boron-rich (FeB)PtNb remainder phase. The ribbons annealed at 700 deg. C for 1 h exhibit promising hard-magnetic properties at room temperature: M{sub r}/M{sub s}=0.69; H{sub c}=820 kA/m and (BH){sub max}=70 kJ/m{sup 3}. Strong exchange coupling between hard and soft magnetic phases was demonstrated by a smooth demagnetizing curve and positive {delta}M-peak in the Henkel plot. The magnetic properties measured from 5 to 750 K reveals that the hard characteristics remains rather stable up to 550 K, indicating a good prospect for the use of these permanent magnets in a wide temperature range.

• OSTI ID: 21476608
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 9; Other Information: DOI: 10.1063/1.3504245; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ANNEALING
BORON ALLOYS
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
CRYSTALS
DEMAGNETIZATION
EXCHANGE INTERACTIONS
IRON 57
IRON ALLOYS
IRON BORIDES
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MICROSTRUCTURE
MOESSBAUER EFFECT
NANOSTRUCTURES
NIOBIUM ALLOYS
PLATINUM ALLOYS
SQUID DEVICES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ALLOYS
BORIDES
BORON COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRONIC EQUIPMENT
EQUIPMENT
EVEN-ODD NUCLEI
FLUXMETERS
HEAT TREATMENTS
INTERACTIONS
INTERMEDIATE MASS NUCLEI
IRON COMPOUNDS
IRON ISOTOPES
ISOTOPES
MATERIALS
MEASURING INSTRUMENTS
MICROSCOPY
MICROWAVE EQUIPMENT
NUCLEI
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
SCATTERING
STABLE ISOTOPES
SUPERCONDUCTING DEVICES
TRANSITION ELEMENT ALLOYS
TRANSITION ELEMENT COMPOUNDS