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Artificially produced rare-earth free cosmic magnet.

Makino A, Sharma P, Sato K, Takeuchi A, Zhang Y, Takenaka K - Sci Rep (2015)

Bottom Line: Electron diffraction detects four-fold 110 superlattice reflections and a high chemical order parameter (S  0.8) for the developed L10-FeNi phase.The magnetic field of more than 3.5 kOe is required for the switching of magnetization.Experimental results along with computer simulation suggest that the ordered phase is formed due to three factors related to the amorphous state: high diffusion rates of the constituent elements at lower temperatures when crystallizing, a large driving force for precipitation of the L10 phase, and the possible presence of L10 clusters.

View Article: PubMed Central - PubMed

Affiliation: Tohoku University, Sendai 980-8577, Japan.

ABSTRACT
Chemically ordered hard magnetic L10-FeNi phase of higher grade than cosmic meteorites is produced artificially. Present alloy design shortens the formation time from hundreds of millions of years for natural meteorites to less than 300 hours. Electron diffraction detects four-fold 110 superlattice reflections and a high chemical order parameter (S  0.8) for the developed L10-FeNi phase. The magnetic field of more than 3.5 kOe is required for the switching of magnetization. Experimental results along with computer simulation suggest that the ordered phase is formed due to three factors related to the amorphous state: high diffusion rates of the constituent elements at lower temperatures when crystallizing, a large driving force for precipitation of the L10 phase, and the possible presence of L10 clusters. Present results can resolve mineral exhaustion issues in the development of next-generation hard magnetic materials because the alloys are free from rare-earth elements, and the technique is well suited for mass production.

No MeSH data available.


Related in: MedlinePlus

Experimental (black) and calculated X-ray diffraction patterns (red) of the L10 phase.Right inset is a magnified graph at 2θ ranging from 20 to 30 degrees for the (001) super-lattice diffraction. Left inset demonstrates the atomic arrangements of the L10 phase with Fe (blue) and Ni (red) atoms drawn with lattice parameters of a = 3.560 and c = 3.615 Å.
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f1: Experimental (black) and calculated X-ray diffraction patterns (red) of the L10 phase.Right inset is a magnified graph at 2θ ranging from 20 to 30 degrees for the (001) super-lattice diffraction. Left inset demonstrates the atomic arrangements of the L10 phase with Fe (blue) and Ni (red) atoms drawn with lattice parameters of a = 3.560 and c = 3.615 Å.

Mentions: The as-quenched state of the Fe42Ni41.3Si8B4P4Cu0.7 alloy is amorphous and its crystallization temperature measured by differential scanning calorimetry (DSC) is ~400 °C (at a heating rate of 40 °C/minute). Figure 1 shows the X-ray diffraction (XRD) pattern of the Fe42Ni41.3Si8B4P4Cu0.7 ribbon crystallized at 400 °C for 288 hours. The diffraction peaks corresponding to the ordered L10 FeNi phase (inset of Fig. 1) along with α-Fe and Fe3B phases are also detected.


Artificially produced rare-earth free cosmic magnet.

Makino A, Sharma P, Sato K, Takeuchi A, Zhang Y, Takenaka K - Sci Rep (2015)

Experimental (black) and calculated X-ray diffraction patterns (red) of the L10 phase.Right inset is a magnified graph at 2θ ranging from 20 to 30 degrees for the (001) super-lattice diffraction. Left inset demonstrates the atomic arrangements of the L10 phase with Fe (blue) and Ni (red) atoms drawn with lattice parameters of a = 3.560 and c = 3.615 Å.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644987&req=5

f1: Experimental (black) and calculated X-ray diffraction patterns (red) of the L10 phase.Right inset is a magnified graph at 2θ ranging from 20 to 30 degrees for the (001) super-lattice diffraction. Left inset demonstrates the atomic arrangements of the L10 phase with Fe (blue) and Ni (red) atoms drawn with lattice parameters of a = 3.560 and c = 3.615 Å.
Mentions: The as-quenched state of the Fe42Ni41.3Si8B4P4Cu0.7 alloy is amorphous and its crystallization temperature measured by differential scanning calorimetry (DSC) is ~400 °C (at a heating rate of 40 °C/minute). Figure 1 shows the X-ray diffraction (XRD) pattern of the Fe42Ni41.3Si8B4P4Cu0.7 ribbon crystallized at 400 °C for 288 hours. The diffraction peaks corresponding to the ordered L10 FeNi phase (inset of Fig. 1) along with α-Fe and Fe3B phases are also detected.

Bottom Line: Electron diffraction detects four-fold 110 superlattice reflections and a high chemical order parameter (S  0.8) for the developed L10-FeNi phase.The magnetic field of more than 3.5 kOe is required for the switching of magnetization.Experimental results along with computer simulation suggest that the ordered phase is formed due to three factors related to the amorphous state: high diffusion rates of the constituent elements at lower temperatures when crystallizing, a large driving force for precipitation of the L10 phase, and the possible presence of L10 clusters.

View Article: PubMed Central - PubMed

Affiliation: Tohoku University, Sendai 980-8577, Japan.

ABSTRACT
Chemically ordered hard magnetic L10-FeNi phase of higher grade than cosmic meteorites is produced artificially. Present alloy design shortens the formation time from hundreds of millions of years for natural meteorites to less than 300 hours. Electron diffraction detects four-fold 110 superlattice reflections and a high chemical order parameter (S  0.8) for the developed L10-FeNi phase. The magnetic field of more than 3.5 kOe is required for the switching of magnetization. Experimental results along with computer simulation suggest that the ordered phase is formed due to three factors related to the amorphous state: high diffusion rates of the constituent elements at lower temperatures when crystallizing, a large driving force for precipitation of the L10 phase, and the possible presence of L10 clusters. Present results can resolve mineral exhaustion issues in the development of next-generation hard magnetic materials because the alloys are free from rare-earth elements, and the technique is well suited for mass production.

No MeSH data available.


Related in: MedlinePlus