Spin-Transfer Torque Magnetic Recording Device for Crosstalk Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The downscaling of magnetic materials in magnetic recording devices leads to challenges in locally controlling magnetization due to the inherent spreading nature of magnetic fields, resulting in crosstalk and inadequate magnetic field strength for controlling magnetization direction, which affects recording density and precision.
Innovation Solution
A magnetic recording device with a laminated structure comprising a first ferromagnetic layer, a second ferromagnetic layer with variable magnetization, and a nonmagnetic layer in between, where electrons spin-polarized by a current perpendicular to the film plane act on the second ferromagnetic layer, and a magnetic field generated by the precession of a third ferromagnetic layer is applied to control the magnetization direction, allowing for efficient magnetization reversal and reduced crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic field is used to control magnetization direction, then magnetization control is achieved, but magnetic field spreads in space causing crosstalk to adjacent bits
Solution Approach 1:
The patent replaces the conventional current-induced magnetic field approach with spin injection induced magnetization reversal. Instead of using a magnetic field that spreads through space, the invention uses spin-polarized electrons to directly transfer angular momentum to the magnetic recording layer, enabling localized control without magnetic field spreading and eliminating crosstalk to adjacent bits.
Solution Approach 2:
The patent changes the fundamental mechanism from magnetic field-based control to spin injection-based control. By altering the physical parameter from magnetic field intensity to spin-polarized electron current density, the system achieves localized magnetization reversal without the spatial spreading inherent in magnetic field methods.
2Object-affected harmful factors
If source of magnetic field is downsized to localize magnetic field, then crosstalk is reduced, but magnetic field strength becomes insufficient to control magnetization direction
Solution Approach 1:
The patent substitutes the magnetic field-based approach with spin injection induced magnetization reversal. This replacement allows for effective magnetization control at the nanoscale without relying on magnetic field strength, as the spin-polarized electrons directly transfer angular momentum to the magnetic recording layer, enabling both localization and sufficient control capability.
Solution Approach 2:
The patent changes the control mechanism from magnetic field strength to spin injection current density. This parameter change enables effective magnetization reversal in downsized magnetic materials without the magnetic field strength deficiency that would otherwise limit further downscaling.
3Quantity of substance
If downscaling of magnetic materials is performed, then recording density is increased, but local control of magnetization becomes difficult due to magnetic field spreading
Solution Approach 1:
The patent replaces conventional magnetic field-based write methods with spin injection induced magnetization reversal. This substitution is critical for downscaling because it eliminates magnetic field spreading, enabling precise local control of magnetization in increasingly smaller magnetic recording layers while maintaining high recording density.
Solution Approach 2:
The patent changes the write mechanism from magnetic field to spin injection current. This parameter change enables effective magnetization control in downsized magnetic materials, allowing recording density to be increased without sacrificing magnetization control precision due to magnetic field spreading.
4Measurement precision
If conventional current-induced magnetic field method is used, then magnetization control is achieved, but write current value cannot be decreased with downscaling
Solution Approach 1:
The patent substitutes the current-induced magnetic field method with spin injection induced magnetization reversal. This replacement enables the write current value to be decreased in accordance with the downscaling of magnetic materials, as the spin injection mechanism is more efficient and scalable than conventional magnetic field generation methods.
Solution Approach 2:
The patent changes the write mechanism from current-induced magnetic field to spin injection current. This parameter change allows the write current value to scale down with the magnetic material size, reducing energy consumption while maintaining magnetization control precision.
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 precise control of magnetization at the nanoscale, increases recording density, and reduces the variation in magnetization reversal, while also decreasing the required write current and maintaining thermal fluctuation resistance and magnetoresistive effect characteristics.
Implementation Method 1
electrons spin-polarized by passing a current in a direction generally perpendicular to the film plane
Implementation Method 2
The angular momentum of spin-polarized electrons is transferred to electrons in a magnetic material serving as a magnetic recording layer, and thereby the magnetization of the magnetic recording layer is reversed.
Implementation Method 3
a magnetic field generated by precession of the magnetization of the third ferromagnetic layer to act on the second ferromagnetic layer
Implementation Method 4
magnetic field generated by precession of the magnetization of the third ferromagnetic layer
Data Source
AI summary
An example magnetic recording device includes a magnetic recording section and a magnetization oscillator and a first nonmagnetic layer disposed between the magnetic recording section and the magnetization oscillator. The magnetic recording section includes a first ferromagnetic layer with a magnetization substantially fixed in a first direction; a second ferromagnetic layer with a variable magnetization direction; and a second nonmagnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer. The magnetization oscillator includes a third ferromagnetic layer with a variable magnetization direction; a fourth ferromagnetic layer with a magnetization substantially fixed in a second direction; and a third nonmagnetic layer disposed between the third ferromagnetic layer and the fourth ferromagnetic layer.