Granular Ru Interlayer with High Permeability Grain Boundaries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reducing the interlayer thickness in perpendicular magnetic recording media while maintaining a narrow c-axis dispersion and avoiding negative impacts on bit error rate performance is challenging, as thinner interlayers can lead to increased switching field distribution and c-axis dispersion in magnetic grains.
Innovation Solution
A granular Ru intermediate layer with high permeability magnetic grain boundaries is used, allowing for a reduced effective magnetic thickness of the interlayer, achieved through co-sputtering or sputtering with composite targets, maintaining a narrow c-axis dispersion and small grain size without the need for a thick Ru interlayer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the interlayer thickness is reduced to increase areal density, then the areal density is improved, but the c-axis dispersion in recording layers increases leading to worse bit error rate performance
Solution Approach 1:
The patent changes the magnetic properties parameter of the interlayer by introducing high permeability grain boundaries into the Ru interlayer structure. This allows the interlayer to maintain effective magnetic shielding and c-axis control functions at reduced thicknesses (5-15 nm), thereby improving areal density while preventing c-axis dispersion and maintaining bit error rate performance.
Solution Approach 2:
The patent creates a composite interlayer structure combining Ru matrix with high permeability magnetic grain boundaries. This composite structure integrates the benefits of both Ru (crystal structure matching, surface morphology control) and high permeability magnetic material (magnetic flux shunting, c-axis control), enabling thin interlayer design that maintains both areal density and reliability.
2Quantity of substance
If the Ru interlayer thickness is reduced to improve areal density, then the areal density is improved, but the switching field distribution increases
Solution Approach 1:
The patent modifies the magnetic permeability parameter of the interlayer by incorporating high permeability grain boundaries. This parameter change enables the thin interlayer (5-15 nm) to maintain effective magnetic control over the recording layer, ensuring narrow switching field distribution while achieving high areal density.
Solution Approach 2:
The high permeability magnetic grain boundaries act as intermediary elements between the Ru interlayer and the recording layer. These grain boundaries provide magnetic flux pathways that mediate the interaction between the thin interlayer and recording layer, ensuring proper magnetic coupling and narrow switching field distribution despite reduced interlayer thickness.
3Reliability
If a thick Ru interlayer is used to maintain narrow c-axis dispersion, then the c-axis dispersion is controlled, but the interlayer thickness increases reducing areal density
Solution Approach 1:
The patent changes the magnetic permeability parameter of the interlayer structure by introducing high permeability grain boundaries within the Ru interlayer. This parameter enhancement allows the interlayer to maintain effective c-axis control and magnetic flux management at reduced thicknesses of 5-15 nm, thereby achieving narrow c-axis dispersion while improving areal density.
4Quantity of substance
If the interlayer thickness is reduced to increase areal density, then the areal density is improved, but the head/media separation is affected
Solution Approach 1:
The patent enhances the magnetic permeability parameter of the interlayer by incorporating high permeability grain boundaries in the Ru interlayer structure. This parameter change allows the thin interlayer (5-15 nm) to maintain adequate magnetic shielding and head/media separation performance while enabling reduced areal density requirements to be met.
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
This approach enables a significant reduction in interlayer thickness to as low as 2-3 nm, improving areal density and bit error rate performance by maintaining a narrow c-axis dispersion and small grain size, while reducing the effective magnetic thickness, thus addressing the limitations of traditional Ru interlayers.
Implementation Method 1
The grain boundaries are made from magnetic materials with high permeability, which provides a path for magnetic flux for the writing process
Implementation Method 2
achieved through co-sputtering or sputtering with composite targets
Data Source
AI summary
A perpendicular magnetic recording (PMR) media including a non-magnetic or superparamagnetic grain isolation magnetic anisotropy layer (GIMAL) to provide a template for initially well-isolated small grain microstructure as well as improvement of Ku in core grains of a magnetic recording layer. The GIMAL composition may be adjusted to have lattice parameters similar to a bottom magnetic recording layer and to provide a buffer for reducing interface strains caused by lattice mismatch between the bottom magnetic recording layer and an underlying layer.