Grounded Plasmon Generator for Thermal-Assisted Magnetic Recording
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic recording technologies face challenges in increasing recording density due to the thermal instability of small magnetic microparticles, which leads to increased coercive force and difficulty in recording information, and the use of plasmon antennas results in excessive temperature increase and shape deformation due to static electricity discharge.
Innovation Solution
A magnetic recording element with a plasmon generator electrically connected to a substrate via a grounding element, preventing static electricity accumulation and heat generation, and maintaining the shape of the plasmon generator, allowing for efficient near-field light generation and stable recording.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the size of magnetic microparticles is decreased to increase recording density, then recording density is improved, but thermal stability of magnetization decreases
Solution Approach 1:
The patent changes the magnetic anisotropy energy parameter by using perpendicular magnetic anisotropy (PMA) instead of in-plane anisotropy. This allows smaller magnetic particles to maintain thermal stability through high perpendicular anisotropy energy, enabling increased recording density without sacrificing thermal stability.
Solution Approach 2:
The patent employs composite magnetic structures including CoFeB/Main Pole, CoFeB/Return Pole, and Ta underlayers to achieve perpendicular magnetic recording. These composite materials provide both the necessary perpendicular anisotropy and thermal stability for high-density recording.
2Stability of the object's composition
If anisotropic energy of magnetic microparticles is increased to improve thermal stability, then thermal stability is improved, but coercive force increases making recording difficult
Solution Approach 1:
The patent utilizes perpendicular magnetic anisotropy (PMA) to change the magnetic anisotropy parameter, achieving high thermal stability through perpendicular orientation while maintaining lower coercive force compared to in-plane anisotropy, thus facilitating easier recording.
Solution Approach 2:
The patent applies perpendicular magnetic anisotropy locally at the magnetic recording medium layer with specific material compositions (CoFeB, Ta underlayers) to achieve high thermal stability only where needed, while the overall system maintains manageable coercive force through the perpendicular recording geometry.
3Temperature
If plasmon antenna is used to generate near field light for thermal assistance, then heating capability is improved, but temperature increase causes volume expansion and shape deformation
Solution Approach 1:
The patent introduces a waveguide as an intermediary component to deliver laser light to the magnetic recording medium for thermal assistance, replacing the direct plasmon antenna approach. This mediator enables controlled heating without the excessive temperature rise that causes plasmon antenna deformation.
Solution Approach 2:
The patent replaces the mechanical/plasmonic near-field light generation system with an optical waveguide system, substituting the plasmon antenna's direct light conversion mechanism with a guided light delivery system that provides more stable thermal assistance without shape deformation issues.
4Illumination intensity
If plasmon antenna is directly irradiated with light to generate near field light, then near field light generation is achieved, but conversion efficiency is low and most energy is reflected or converted to heat
Solution Approach 1:
The patent uses a waveguide as an intermediary to efficiently deliver laser light to the magnetic recording medium, avoiding the energy loss associated with direct plasmon antenna irradiation. The waveguide provides controlled light propagation with minimal reflection and heat conversion losses.
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 solution effectively reduces static electricity-induced heat and maintains the shape of the plasmon generator, enhancing the efficiency of near-field light generation and improving recording density without compromising the shape, thus overcoming the limitations of conventional technologies.
Implementation Method 1
The overlapping part of the propagation edge is coupled with the laser light propagating through the waveguide in a surface plasmon mode so that a surface plasmon is generated
Implementation Method 2
The propagation edge propagates the surface plasmon generated in the overlapping part to the near field light generator
Data Source
AI summary
A plasmon generator positioned away from the substrate and extending to the air bearing surface (ABS) as facing a part of the waveguide. The plasmon generator has a propagation edge extending in a longitudinal direction. The propagation edge has an overlapping part overlapping the waveguide in the longitudinal direction, and a near field light generator positioned on the ABS and located in the vicinity of the edge part of the recording magnetic pole. The overlapping part of the propagation edge is coupled with the laser light propagating through the waveguide in a surface plasmon mode so that a surface plasmon is generated. The propagation edge propagates the surface plasmon generated in the overlapping part to the near field light generator. The magnetic recording element further has a grounding element electrically connecting the plasmon generator and the substrate.