| 摘要 |
<p>PROBLEM TO BE SOLVED: To form an image having high image quality with an Li-Mn ferrite carrier contg. no harmful element by imparting a basic compsn. consisting of Li2 O, MnO and Fe2 O3 in a specified molar ratio to Li-Mn ferrite and specifying the vol. resistivity, specific surface area and average particle diameter of the ferrite. SOLUTION: Lithium-manganese ferrite having a basic compsn. consisting of, by mol, 5-15% Li2 O, 8-30% MnO and 60-90% Fe2 O3 and having 10<5> -10<13>Ω.cmvol. resistivity, 0.1-0.3m<2> /g specific surface area and 10-100μm average particle diameter is used as a magnetic carrier and bias voltage obtd. by superposing AC bias voltage having 500V to 2.5kV peak-to-peak voltage and 100Hz to 10kHz frequency on DC bias voltage is impressed on a sleeve 5. A coating layer made chiefly of a resin material may be formed on the surface of the magnetic carrier.</p> |
