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Perpendicularly easy-axis orientated artificially synthetic antiferromagnet and pseudo-spin valve film structure

A technology of artificial synthesis and antiferromagnet, which is applied in the direction of spin-exchange coupling multilayer film, magnetic layer, magnetic recording head, etc., can solve the problems of disappearance, small difference in flipping field, and signal reduction, and achieve good stability and signal Excellent thermal stability effect

Inactive Publication Date: 2015-01-07
FUDAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the general vertical magnetic anisotropic spin valve, the difference between the flip field of the free layer and the reference layer is generally relatively small, and this difference even disappears when the temperature rises, causing the magnetization to flip at the same time, so that the signal decreases or even disappears.

Method used

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  • Perpendicularly easy-axis orientated artificially synthetic antiferromagnet and pseudo-spin valve film structure
  • Perpendicularly easy-axis orientated artificially synthetic antiferromagnet and pseudo-spin valve film structure
  • Perpendicularly easy-axis orientated artificially synthetic antiferromagnet and pseudo-spin valve film structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Structure: Corning Glass / Ta 3.0nm / Cu 1.4nm / [Ni 0.59nm / Co 0.25nm] 3 / Ru 0.4-1.2nm / [Co0.25nm / Ni 0.59nm] 5 / Ta 3.0nm.

[0029] This example is a group of artificially synthesized antiferromagnetic structures with a nonferromagnetic Ru layer with a thickness of 0.4-1.2 nm. Such as image 3 As shown, when the thickness of the Ru layer is 0.5-0.9nm, it shows antiferromagnetic coupling. When the thickness is small, the coupling strength increases with the thickness. When the thickness is 0.7nm, the antiferromagnetic coupling reaches the strongest, and the coupling field size is 4640Oe, after that the coupling strength decreases with increasing thickness. When the thickness of Ru decreases to 0.4nm or increases to 1.2nm, the antiferromagnetic coupling disappears and becomes ferromagnetic coupling.

Embodiment 2

[0031] Structure: Corning Glass / Ta 3.0nm / Cu 1.4nm / [Ni 0.59nm / Co 0.33nm] N / Ru 0.7nm / [Co0.25nm / Ni 0.59nm] 3 / Ta 3.0nm.

[0032] This example is a group of artificially synthesized antiferromagnetic structures with a [Co / Ni] multilayer film period number N of 2-5. Such as Figure 4 As shown, the good perpendicular magnetic anisotropy is maintained when the number of periods increases from 2 to 5. When the number of periods is 4, the magnetic moments of the upper and lower magnetic multilayer films remain antiparallel in the larger magnetic field range near zero field, which is beneficial to obtain excellent giant magnetoresistance spin valve performance.

Embodiment 3

[0034] Structure: Corning Glass / Ta 3.0nm / Cu 1.4nm / [Ni 0.59nm / Co 0.33nm] N / Cu 2.3nm / [Co0.33nm / Ni 0.59nm] 4 / Ru 0.7nm / [Co 0.25nm / Ni 0.59nm] 3 / Ta 3.0nm.

[0035] This example is a group of artificially synthesized antiferromagnetic pseudo-spin valve samples with a free layer [Co / Ni] multilayer film period number N of 2-4. Such as Figure 5 As shown, when the period number is 2, the vertical anisotropy is not very good, and the signal is only 4.2%; when the period number is 3, the sample has good vertical anisotropy, the giant magnetoresistance signal can reach 6.0%, and the high There is a difference of up to 800Oe between the flipping fields of the free layer and the reference layer at the time of the signal; when the period number N is 4, the giant magnetoresistance signal is similar to that of N=3, but the perpendicular anisotropy becomes worse, and the difference of the magnetic flipping field also decreases. small.

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Abstract

The invention belongs to the technical field of magnetic recording, in particular to a perpendicularly easy-axis orientated artificially synthetic antiferromagnet and a pseudo-spin valve film structure. The perpendicularly easy-axis orientated artificially synthetic antiferromagnet of the invention has a sandwich structure formed by two perpendicularly magnetized [Co / Ni] multilayer membranes isolated by a non-magnetic layer Ru inbetween. The pseudo-spin valve film structure adopts the artificially synthetic antiferromagnet as a magnetic reference layer. A single [Co / Ni] multilayer membrane serves as a free layer. Different strengths of coupling between antiferromagnet layers can be obtained by adjusting the thickness of the Ru layer. The size of a giant magnetoresistance signal and the thermostability of a pseudo-spin valve can be modulated by adjusting the periodicity of the [Co / Ni] multilayer membranes. The difference between the magnetization switching fields of the free layer and the reference layer can reach 800Oe, and the giant magnetoresistance signal is over 6.0 percent at room temperature and can still retain over 5.0 percent after being treated by heating at 300 DEG C, so the pseudo-spin valve has high thermostability. The antiferromagnet and the structure have high use value in computer hardware reading heads, MRAMs and other pseudo-spin electronic elements.

Description

technical field [0001] The invention belongs to the technical field of magnetic recording, and in particular relates to a high-density non-volatile magnetic random access memory and other spin electronic devices, in particular to an artificially synthesized antiferromagnetic pseudo-spin valve with perpendicular magnetic anisotropy. Background technique [0002] Since the artificially synthesized antiferromagnetic structure can reduce the interlayer magnetostatic coupling and reduce the demagnetization field of the pinning layer, it has been widely used in traditional in-plane magnetization giant magnetoresistance spin valves and magnetic tunnel junction devices, and in hard disks. Play an important role in the read head and magnetic random access memory. In recent years, the many advantages of perpendicular magnetization spin valves, such as strong magnetic stability, high information storage density, and flipping reliability, have provided the possibility for the design and...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F10/12H01F10/26H01F10/32H01F41/18G11B5/39
Inventor 张宗芝贺赫马斌金庆原
Owner FUDAN UNIV