Oxide Exchange Coupling Layer for Perpendicular Magnetic Recording Media
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Solution Overview
Problem
Current perpendicular magnetic recording media face challenges in achieving high recording density with low bit error rate, signal-to-noise ratio (SNR), and overwrite (OW) due to the trade-off among magnetic core width (MCW), SNR, and OW, and require new materials for the exchange coupling layer to improve these parameters.
Innovation Solution
A magnetic storage medium with a substrate, a first and second oxide magnetic layer, an oxide-containing exchange coupling layer, and a magnetic cap layer, where the exchange coupling layer is formed with varying oxygen flow conditions to optimize Ku values and layer thicknesses, using materials like CoCrPt-oxide, which enhances magnetic decoupling and noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high Ku magnetic materials are used to keep small grains stable, then magnetic stability is improved, but writability deteriorates and media noise increases
Solution Approach 1:
The magnetic recording layer is segmented into multiple layers with different Ku values. The lower Ku layer (5-15 eV) provides writability and lower media noise, while the upper Ku layer (15-30 eV) provides magnetic stability. This segmentation allows each layer to perform its specialized function without compromising the other.
Solution Approach 2:
The invention uses a composite magnetic recording structure with two distinct magnetic layers having different magnetic anisotropy energies. This composite approach combines the benefits of high stability (from high Ku layer) and good writability (from low Ku layer) that cannot be achieved with a single material.
2Reliability
If the Ku of the recording layer increases to maintain small grain stability, then magnetic stability is improved, but media noise increases
Solution Approach 1:
The magnetic recording layer is segmented into multiple layers with different Ku values. The lower Ku layer (5-15 eV) provides writability and lower media noise, while the upper Ku layer (15-30 eV) provides magnetic stability. This segmentation allows each layer to perform its specialized function without compromising the other.
3Reliability
If exchange coupled composite media comprising hard and soft layers are used, then SNR and OW are improved, but the trilemma among SNR, OW, and MCW remains
Solution Approach 1:
The invention changes the magnetic anisotropy energy parameter by creating a vertical gradient from low Ku (5-15 eV) at the bottom to high Ku (15-30 eV) at the top. This parameter gradient allows the system to achieve improved SNR and OW while maintaining acceptable MCW, effectively resolving the traditional trilemma constraint.
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 proposed solution improves the magnetic storage medium's performance by achieving high Ku values, low noise, and narrow magnetic core width, while maintaining good OW and SNR over a wide range of cap layer thicknesses, effectively addressing the trilemma of MCW, SNR, and OW.
Implementation Method 1
an exchange coupling layer formed above the second oxide magnetic layer, the exchange coupling layer comprising an oxide
Implementation Method 2
forming a high Ku first oxide magnetic layer above a substrate by sputtering
Data Source
AI summary
A method according to one embodiment includes forming a high Ku first oxide magnetic layer above a substrate by sputtering; forming a low Ku second oxide magnetic layer above the first oxide magnetic layer by sputtering; forming an exchange coupling layer of CoCrPt-oxide above the second oxide magnetic layer; and forming a magnetic cap layer above the exchange coupling layer. Additional systems and methods are also presented.