Ruthenium-Doped Z-Type Hexaferrite for Low Magnetic Loss
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Solution Overview
Problem
Developing ferrite materials for high-frequency applications is challenging due to high magnetic loss in existing hexaferrites, limiting their use in ultrahigh frequency, L-band, and S-band devices despite their potential for high ferromagnetic resonance frequencies and permeabilities.
Innovation Solution
A ruthenium-doped Z-type hexaferrite (Ru—Co2Z) with the formula (Ba3-xMx)Co2(M′Ru)yFe24-2y-zO41 is developed, where M is Sr, Pb, or Ca, and M′ is Co, Zn, or Cu, offering improved permeability and reduced magnetic loss, suitable for S-L band frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cobalt-substituted barium Y-type or Z-type hexaferrites are used to achieve high ferromagnetic resonance frequencies and permeabilities, then magnetic performance is improved, but magnetic loss increases
Solution Approach 1:
The patent changes the chemical composition parameters by substituting ruthenium for iron in the hexaferrite structure and adjusting the ratio of barium to other alkaline earth metals. This parameter change modifies the magnetic properties to achieve high ferromagnetic resonance frequency and permeability while simultaneously reducing magnetic loss, resolving the contradiction between improved magnetic performance and reduced energy loss.
Solution Approach 2:
The patent creates a composite ferrite material with multiple cations (barium, ruthenium, iron, and other alkaline earth metals) in specific ratios. This composite approach allows optimization of magnetic properties by combining elements with different characteristics, achieving both high ferromagnetic resonance frequency and low magnetic loss that cannot be obtained with single-substitution approaches.
2Ease of manufacture
If conventional ferrite materials are used for high frequency applications, then ease of manufacture is maintained, but magnetic loss at high frequencies is high
Solution Approach 1:
The patent modifies the chemical composition parameters of conventional ferrite materials by introducing ruthenium substitution and adjusting alkaline earth metal ratios. These parameter changes reduce magnetic loss at high frequencies while maintaining compatibility with conventional sintering processes, thus preserving ease of manufacture while improving high-frequency performance.
3Reliability
If Z-type ferrites are used for high impedance magneto-dielectric composites, then impedance performance is improved, but magnetic loss limits their use
Solution Approach 1:
The patent changes the compositional parameters of Z-type ferrite by substituting ruthenium for iron and adjusting the barium to alkaline earth metal ratio. These parameter changes reduce magnetic loss while maintaining the high impedance characteristics necessary for magneto-dielectric composites, resolving the limitation that previously prevented practical application.
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 Ru—Co2Z ferrite exhibits high permeability, low magnetic loss, and suitable operating frequencies, making it suitable for use in antennas and inductors within the ultrahigh frequency range with reduced dielectric and magnetic loss tangents.
Implementation Method 1
Some hexaferrites, such as cobalt-substituted barium Y-type (Co2Y) and Z-type (Co2Z) hexaferrites, can have much higher ferromagnetic resonance frequencies and permeabilities
Implementation Method 2
substituting at least a portion of the iron ion in a Z-type hexaferrite with ruthenium can result in a Ru—Co2Z ferrite with improved properties
Data Source
AI summary
In an aspect, a ferrite composition comprises a Ru—Co2Z ferrite having the formula: (Ba3-xMx)Co2(M′Ru)yFe24-2y-zO41, wherein M is at least one of Sr, Pb, or Ca; M′ is at least one of Co, Zn, Mg, or Cu; x is 1 to 3; y is greater than 0 to 2; and z is −4 to 4. In another aspect, an article comprises the ferrite composition. In yet another aspect, method of making the ferrite composition comprises mixing ferrite precursor compounds comprising Fe, Ba, Co, and Ru; and sintering the ferrite precursor compounds in an oxygen atmosphere to form the Ru—Co2Z ferrite.