Chemical Synthesis of Magnetically Hard and Strong Rare Earth Metal Based Nanomagnets.
Angew Chem Int Ed Engl
; 58(2): 602-606, 2019 Jan 08.
Article
em En
| MEDLINE
| ID: mdl-30414238
ABSTRACT
We report a general chemical approach to synthesize strongly ferromagnetic rare-earth metal (REM) based SmCo and SmFeN nanoparticles (NPs) with ultra-large coercivity. The synthesis started with the preparation of hexagonal CoO+Sm2 O3 (denoted as SmCo-O) multipods via decomposition of Sm(acac)3 and Co(acac)3 in oleylamine. These multipods were further reduced with Ca at 850 °C to form SmCo5 NPs with sizes tunable from 50 to 200â
nm. The 200â
nm SmCo5 NPs were dispersed in ethanol, and magnetically aligned in polyethylene glycol (PEG) matrix, yielding a PEG-SmCo5 NP composite with the room temperature coercivity (Hc ) of 49.2â
kOe, the largest Hc among all ferromagnetic NPs ever reported, and saturated magnetic moment (Ms ) of 88.7â
emu g-1 , the highest value reported for SmCo5 NPs. The method was extended to synthesize other ferromagnetic NPs of Sm2 Co17 , and, for the first time, of Sm2 Fe17 N3 NPs with Hc over 15â
kOe and Ms reaching 127.9â
emu g-1 . These REM based NPs are important magnetic building blocks for fabrication of high-performance permanent magnets, flexible magnets, and printable magnetic inks for energy and sensing applications.
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MEDLINE
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2019
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Article