| 摘要 |
PROBLEM TO BE SOLVED: To provide ferrite particles that suppress the generation of cracks and chipping when used as a carrier core material of an image forming apparatus of an electrophotographic system even when the speed of image formation is increased.SOLUTION: There is provided ferrite particles represented by a composition formula MFeO, wherein M is at least one metal selected from the group consisting of Mg, Mn, Ca, Sr, Ti, Cu, Zn, and Ni, and 0≤X≤1, where a first average particle diameter is in a range from 20 μm to 30 μm; after the ferrite particles are screened so that particles on a sieve have an average particle diameter larger than the first average particle diameter by 10 μm, the shape coefficient SF-1 of the particles on a sieve is 127; the ratio of particles having a shape coefficient SF-1 of 140 or more is 6 number% or less.SELECTED DRAWING: Figure 1 |
