US 11,721,461 B2
Particles of magnetoplumbite-type hexagonal ferrite, method for manufacturing the same, and radio wave absorber
Yoichi Hosoya, Minami-Ashigara (JP); Masashi Shirata, Minami-Ashigara (JP); and Tatsuo Mikami, Minami-Ashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Jun. 18, 2020, as Appl. No. 16/904,932.
Application 16/904,932 is a continuation of application No. PCT/JP2018/047650, filed on Dec. 25, 2018.
Claims priority of application No. 2017-252035 (JP), filed on Dec. 27, 2017.
Prior Publication US 2020/0335247 A1, Oct. 22, 2020
Int. Cl. H01F 1/34 (2006.01); H01F 1/37 (2006.01); C01G 49/00 (2006.01); H05K 9/00 (2006.01); C30B 29/22 (2006.01)
CPC H01F 1/348 (2013.01) [C01G 49/0045 (2013.01); C30B 29/22 (2013.01); H05K 9/0075 (2013.01); C01P 2002/76 (2013.01); C01P 2006/42 (2013.01)] 7 Claims
OG exemplary drawing
 
1. Particles of a magnetoplumbite-type hexagonal ferrite represented by Formula (1) and having a single crystal phase,
AFe(12−x)AlxO19  Formula (1)
in Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5≤x≤8.0,
wherein a number average particle diameter D50 of the particles of the magnetoplumbite-type hexagonal ferrite is 2 μm or more and 100 μm or less, and
wherein a μ″ peak frequency of the particles of the magnetoplumbite-type hexagonal ferrite is equal to or higher than 60 GHz, and a μ″ peak value of the particles of the magnetoplumbite-type hexagonal ferrite is equal to or higher than 0.2.