Precise measurement of magnetization characteristics in high pulsed field

Nakahata, Yasushi; Borkowski, Bartosz; Shimoji, Hiroyasu; Yamada, Kou; Todaka, Toshiyuki; Enokizono, Masato

doi:10.1063/1.3673809

Cited by 3 publications

(6 citation statements)

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“…The advantage of this method is that it allows for the rapid acquisition of isothermal magnetization, and a higher magnetic field can be applied to the samples. This method is widely used for measuring the magnetization of strong magnets [ 53 ], ferromagnetic materials or superconductors [ 54 ] and ferromagnetic powder or volcanic rock [ 55 ]. Moreover, it was demonstrated by Kodama [ 56 ] that the measurement of the magnetization of nanoparticles using this method is acceptable and yields results similar to those yielded by the vibration method.…”

Section: Resultsmentioning

confidence: 99%

Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres

et al. 2022

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The synthesis of magnetic particles triggers the interest of many scientists due to their relevant properties and wide range of applications in the catalysis, nanomedicine, biosensing and magnetic separation fields. A fast synthesis of iron oxide magnetic particles using an eco-friendly and facile microwave-assisted solvothermal method is presented in this study. Submicron Fe3O4 spheres were prepared using FeCl3 as an iron source, ethylene glycol as a solvent and reductor and sodium acetate as a precipitating and nucleating agent. The influence of the presence of polyethylene glycol as an additional reductor and heat absorbent was also evaluated. We reduce the synthesis time to 1 min by increasing the reaction temperature using the microwave-assisted solvothermal synthesis method under pressure or by adding PEG at lower temperatures. The obtained magnetite spheres are 200–300 nm in size and are composed of 10–30 nm sized crystallites. The synthesized particles were investigated using the XRD, TGA, pulsed-field magnetometry, Raman and FTIR methods. It was determined that adding PEG results in spheres with mixed magnetite and maghemite compositions, and the synthesis time increases the size of the crystallites. The presented results provide insights into the microwave-assisted solvothermal synthesis method and ensure a fast route to obtaining spherical magnetic particles composed of different sized nanocrystallites.

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Section: Resultsmentioning

confidence: 99%

Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres

et al. 2022

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“…Figure 15 plots the time dependence of the electrical current I(t) of coil A at room temperature. The red solid line indicates the value of the experimental result, and the dotted line indicates the approximate value calculated using equation (7). In this way, time dependence of I(t) was well explained by considering a pulse magnetic field circuit to be a series LCR circuit in terms of the electrical resistance of the coil.…”

Section: Estimation Of the Electric Current Of The Magnet Considering...mentioning

confidence: 86%

“…The pulse magnetic field system was also used in a study for the the development of a permanent magnet with high coercivity and high saturated magnetization [7,8].…”

Section: Introductionmentioning

confidence: 99%

“…In addition to generating giant magnetic fields, a pulse magnet system has also been used for magnetizing high-T C superconducting magnets, or permanent magnets such as Nd-Fe-B magnets [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…Nakahata et al developed the pulsed magnet system for the magnetization of Nd-Fe-B magnets [7]. The fabricated system was equipped with fourteen 2 mF, 3 kV capacitors and ten 10 mF, 1 kV capacitors, which respectively stored 126 kJ and 50 kJ of electric energy.…”

Section: Introductionmentioning

confidence: 99%

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Home-made pulse magnet power supply for magnetizing permanent magnets and magnetic measurements

Sakon

Kitagawa²,

Miyaoku³

2022

Eng. Res. Express

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In this article, we propose a home-made pulse magnetic field generation system constructed using a thyristor and large capacitance capacitors to generate high magnetic fields to investigate magnetic properties and magnetize the magnet and high-performance magnetic materials at room temperature. The proposed system produced a magnetic induction (magnetic field) μ 0H of 15.6 T with the 33.6 mF capacitor and an excitation voltage of 600 V. Further, we designed a new power supply system and a pulse magnet using the commercially available pulse magnet and power supply. We found that the duration time of the magnetic fields (t d) and the generated magnetic fields were three and four times larger than those for a conventional system, respectively. We also performed magnetization of a NEOMAX permanent magnet; the coercivity (ΒCJ) was 2.0 T, and the magnetization saturated at ~4.0 T. These results suggest that we can magnetise a permanent magnet such as NEOMAX with strong magnetic fields using this system. Further, the magnetic measurements of these magnets can be performed as well. The merit of our system is that the capacitance of the capacitor bank is larger than that of other studies or general commercial power supplies. Therefore, relatively high magnetic fields with long duration time can be generated. We also performed experiments on the magnetization process (M-H) of Gd to investigate the magnetocaloric effect in high magnetic fields. The magnetic entropy change was comparable to the result of former investigation. We believe that our research can contribute to the development of permanent magnets and magnetic materials for scientific and industrial use because our system allows the generation of strong magnetic fields at room temperature.

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Construction of the Pulsed High Magnetic Field Generator up to 33T and the Enhancements of the Magnetic Coercivity in High Fields

Nakahata¹,

Yamada

Luo³

et al. 2012

MSF

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Precise measurement of magnetization characteristics in high pulsed field

Cited by 3 publications

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Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres

Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres

Home-made pulse magnet power supply for magnetizing permanent magnets and magnetic measurements

Construction of the Pulsed High Magnetic Field Generator up to 33T and the Enhancements of the Magnetic Coercivity in High Fields

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