Ferrite Powder Coercive Force and Dispersibility
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Solution Overview
Problem
Existing ferrite powders face challenges in achieving high coercive force and excellent dispersibility in resins or solvents, often resulting in decreased magnetic properties and poor dispersibility, which affects the quality of magnetic recording media and ink.
Innovation Solution
Ferrite powder with specific characteristics: single-crystal particles of 1 nm to 2,000 nm in diameter, polyhedral shape, containing 2.0-10.0% Sr and 55.0-70.0% Fe, which enhances coercive force and dispersibility, and a resin composition incorporating this powder for improved magnetic and electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the dispersibility of magnetic powder in dispersion liquid is improved, then the magnetic properties of the magnetic powder decrease (particularly coercive force decreases)
Solution Approach 1:
The invention changes the particle size parameter to 1 nm or more and 2,000 nm or less, and controls the composition parameters (Sr: 2.0-10.0 mass%, Fe: 55.0-70.0 mass%) to achieve optimal balance between dispersibility and magnetic properties. This parameter optimization resolves the contradiction by finding the sweet spot where both dispersibility and coercive force are maximized
Solution Approach 2:
The invention creates a composite ferrite powder with specific multi-element composition (Sr-Fe-O system with controlled ratios) that combines the benefits of both good dispersibility and high magnetic properties. The composite structure at the nanoscale allows simultaneous achievement of dispersion stability and magnetic performance
2Reliability
If the particle diameter of ferrite powder is reduced, then the coercive force increases, but the dispersibility may deteriorate
Solution Approach 1:
The invention optimizes the particle diameter parameter within the specific range of 1 nm to 2,000 nm, preventing both excessive aggregation (which would occur with very fine particles) and loss of magnetic properties (which would occur with larger particles). This controlled parameter range resolves the contradiction between coercive force and dispersibility
Solution Approach 2:
The invention creates local polyhedral shape characteristics in the ferrite particles, where the local crystal structure and surface morphology are optimized for both magnetic performance and dispersion stability, allowing simultaneous achievement of high coercive force and good dispersibility
3Ease of manufacture
If conventional ferrite powder is used, then manufacturing is simple, but the dispersibility in resin or solvent is poor
Solution Approach 1:
The invention modifies the particle size parameter to the nanoscale range (1-2,000 nm) and controls the composition parameters (Sr: 2.0-10.0 mass%, Fe: 55.0-70.0 mass%), which inherently improves dispersibility while maintaining compatibility with conventional manufacturing processes, thus resolving the contradiction between manufacturing simplicity and dispersibility
Data Source
AI summary
The ferrite powder of the present invention is a ferrite powder containing a plurality of ferrite particles, wherein the ferrite particles each are a single crystal body having an average particle diameter of 1-2,000 nm, and have a polyhedron shape, and wherein the ferrite particles each contain 2.0-10.0 mass % of Sr, and 55.0-70.0 mass % of Fe.