| abstract |
A material expressed as a composition formula M x Fe 3-x O 4 (where M is at least one of Mg and Mn, and 0 ≤ X ≤ 1) is a main component, and as a total amount, 0.1 to 2.5 weight percent of at least one of a Sr element and a Ca element is contained. Here, when ferrite particles are used as a carrier, in terms of obtaining a higher image density, the fluidity of the ferrite particles magnetized under a magnetic field of 1000/(4π) kA/m (1000 oersteds) is preferably 40 seconds or more. The residual magnetization σr is preferably 3 Am 2 /kg or more. |