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US 12,540,082 B2Granted
Cobalt ferrite particle production method and cobalt ferrite particles produced thereby
AssigneeNittetsu Mining Co., Ltd.
InventorsTsubasa Arai, Naoki Muratani, Akira Kishimoto, Hideyuki Takahashi
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Abstract
Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. When a cobalt ferrite precursor is treated at a high temperature and a high pressure, an oxidation reaction is caused in the presence of a complexing agent, thereby obtaining intended cobalt ferrite magnetic particles.
Claims13
A method for producing cobalt ferrite particles, comprising
- forming a ferrite precursor aqueous solution containing a ferrous salt, an oxidant, and a cobalt salt stabilized by a complexing agent in a pressure vessel, and then
- performing a first thermal treatment on the ferrite precursor aqueous solution,
- wherein the entirety of the first thermal treatment is conducted on the ferrite precursor aqueous solution in the presence of the oxidant, and
- wherein the first thermal treatment is performed within a temperature range of 130° C. to 190° C. under a hydrothermal condition.
1 more element
A method, comprising:
- forming a ferrite precursor aqueous solution containing a ferrous salt, an oxidant, and a cobalt salt stabilized by a complexing agent, and then
- performing a thermal treatment on the ferrite precursor aqueous solution,
- wherein the entirety of the thermal treatment is conducted on the ferrite precursor aqueous solution in the presence of the oxidant, and
- wherein the thermal treatment is performed within a temperature range of 130° C. to 190° C. under a hydrothermal condition;
- thereby forming cobalt ferrite particles having a coefficient of variation of particle diameters, a CV value, of 0.1 to 0.3, a rounded shape and an average particle diameter of 5 to 50 μm.
2 more elements
Dependencies are inferred from the claim text.