Aligned Iron Nitride Nanoparticles for Anisotropic Permanent Magnets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rare-earth-free permanent magnetic materials face challenges in aligning nanoparticles due to electrostatic and electromagnetic forces, leading to agglomeration and reduced magnetic properties, such as low energy product and remnant magnetization.
Innovation Solution
The development of aligned iron nitride nanoparticles with α″-Fe16N2 phase domains, which exhibit a specific ratio of integrated x-ray diffraction peak intensities and squareness measurements, overcoming the tendency to form agglomerates and enhancing magnetic properties through controlled processing and alignment techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nanoparticles are used to form rare-earth-free permanent magnets, then abundance and cost are improved, but magnetic properties deteriorate due to agglomeration
Solution Approach 1:
The patent applies preliminary action by aligning nanoparticles in a magnetic field before consolidation occurs. This pre-alignment ensures that even though nanoparticles tend to agglomerate during processing, they maintain their oriented arrangement, preserving magnetic properties like remnant magnetization and energy product while using abundant rare-earth-free materials.
2Manufacturing precision
If external force is used to align nanoparticles, then magnetic anisotropy is improved, but agglomeration worsens due to electrostatic and electromagnetic forces
Solution Approach 1:
The patent uses a binder as an intermediary material that fixes nanoparticles in a matrix after alignment. This binder prevents electrostatic and electromagnetic forces from causing excessive agglomeration, allowing nanoparticles to remain aligned while maintaining stable composition throughout the magnet structure.
Solution Approach 2:
The patent changes physical parameters by controlling the consolidation process under specific conditions (temperature, pressure, magnetic field strength) to balance alignment forces against agglomeration tendencies. By optimizing these parameters, nanoparticles achieve sufficient alignment without forming large porous clusters that would degrade magnetic properties.
3Ease of manufacture
If nanoparticles form agglomerates during processing, then ease of manufacture is improved, but magnetic performance deteriorates due to reduced ability to rotate in response to alignment forces
Solution Approach 1:
The patent applies preliminary action by aligning nanoparticles in a magnetic field before consolidation occurs. This pre-alignment ensures that even though nanoparticles tend to agglomerate during processing, they maintain their oriented arrangement, preserving magnetic properties like remnant magnetization and energy product while using abundant rare-earth-free materials.
Solution Approach 2:
The patent uses a binder as an intermediary material that fixes nanoparticles in a matrix after alignment. This binder prevents electrostatic and electromagnetic forces from causing excessive agglomeration, allowing nanoparticles to remain aligned while maintaining stable composition throughout the magnet structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The aligned iron nitride nanoparticles result in anisotropic nanocomposite magnets with improved squareness and energy product, leading to higher remnant magnetization and coercivity, suitable for advanced magnetic applications.
Implementation Method 1
If the nanoparticles have sufficiently large magnetic anisotropy, an external force may be used to align the nanoparticles prior to and/or during consolidation.
Implementation Method 2
an external force may be used to align the nanoparticles prior to and/or during consolidation
Implementation Method 3
a ratio of integrated intensities of an α′′-Fe16N2 (004) x-ray diffraction peak to an α′′-Fe16N2 (202) x-ray diffraction peak
Implementation Method 4
an external force may be used to align the nanoparticles prior to and/or during consolidation
Implementation Method 5
electrostatic and electromagnetic forces generally combine to cause nanoparticles to form agglomerates
Implementation Method 6
electrostatic and electromagnetic forces generally combine to cause nanoparticles to form agglomerates
Data Source
AI summary
Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include α″-Fe16N2 phase domains; wherein a ratio of integrated intensities of an α″-Fe16N2 (004) x-ray diffraction peak to an α″-α″-Fe16N2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.