Idaho Research Foundation, Inc.

Hong Sik Jung

Patrick R Taylor

Yang-Ki Hong

Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO or SrCO ), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO or KNO ), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles. The particles are used for forming a magnetic recording media by dispersing the particles in a magnetic paint and coating the paint onto a substrate, or by dispersing the particles in a self-supporting material.

Media employing substantially spherical magneto-plumbite ferrite particles

Substantially spherical magneto-plumbite ferrite (barium or strontium ferrite) particles are formed from well-dispersed ultra-fine substantially spherical iron-based oxide and/or hydroxide particles as precursor particles. The precursor particles are mixed with a colloidal barium or strontium carbonate (BaCO,or SrCO,), and with small amounts of a byproduct, such as sodium or potassium chloride (NaCl or KCl) or hydroxide (NaOH or KOH) or nitrate (NaNO,or KNO,), functioning as a flux to lower the calcination temperature. The particles are filtered out of the mixture, dried, and calcined for a time sufficiently long and/or at a temperature sufficiently high to form magneto-plumbite ferrite from the precursor particles, and for a time sufficiently short and/or a temperature sufficiently low to maintain the general spherical shape of the precursor particles. The particles are used for forming a magnetic recording media by dispersing the particles in a magnetic paint and coating the paint onto a substrate, or by dispersing the particles in a self-supporting material.

Growing community of inventors

Moscow, ID, United States of America

Hong Sik Jung