	US 12,260,977 B2
	Powder of magnetoplumbite-type hexagonal ferrite, method for producing the same, and radio wave absorber
Hirokazu Hashimoto, Kanagawa (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Feb. 11, 2021, as Appl. No. 17/173,437.
Application 17/173,437 is a continuation of application No. PCT/JP2019/022347, filed on Jun. 5, 2019.
Claims priority of application No. 2018-159192 (JP), filed on Aug. 28, 2018; and application No. 2019-098735 (JP), filed on May 27, 2019.
Prior Publication US 2021/0166849 A1, Jun. 3, 2021
Int. Cl. H01F 1/34 (2006.01); C01G 49/00 (2006.01); H01Q 17/00 (2006.01)

CPC H01F 1/344 (2013.01) [C01G 49/0072 (2013.01); H01Q 17/00 (2013.01); C01P 2002/72 (2013.01); C01P 2004/02 (2013.01)]

10 Claims

1. A powder of a magnetoplumbite-type hexagonal ferrite which is an aggregate of particles of a compound represented by Formula (1), and

wherein, in a particle size distribution based on number measured by a laser diffraction scattering method, in a case where a mode value is defined as a mode diameter, a diameter at a cumulative percentage of 10% is defined as D₁₀and a diameter at a cumulative percentage of 90% is defined as D₉₀, the mode diameter is equal to or greater than 5 μm and less than 10 μm and an expression of (D₉₀−D₁₀)/mode diameter≤3.0 is satisfied,

AFe_(12-x)Al_xO₁₉ 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.