Magnetic Measurement System Using X-ray Magnetic Circular Dichroism
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Solution Overview
Problem
Conventional methods are unable to accurately measure the magnetic properties of micro-particles and bulk samples due to limitations in focusing X-rays, low sensitivity in detecting X-ray transmittance, and interference from surface oxidized layers, which restricts observation depth and accuracy.
Innovation Solution
A magnetic measurement system using X-ray magnetic circular dichroism with an Avalanche photodiode to measure photo-counts of X-ray transmittance, allowing for precise measurement of magnetic characteristics in thick samples by focusing circularly polarized X-rays and scanning transmission electron microscopy, enabling observation of magnetic properties within external magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods are used to measure magnetic properties of micro-particles, then surface magnetic characteristics can be observed, but measurement precision and accuracy are insufficient due to low sensitivity in detecting X-ray transmittance
Solution Approach 1:
The patent replaces conventional detection methods with an Avalanche photodiode that utilizes the photoelectric effect to detect X-ray transmittance. This substitution of detection mechanism dramatically improves measurement sensitivity and precision for magnetic properties of micro-particles and bulk samples
Solution Approach 2:
The patent employs X-ray magnetic circular dichroism (XMCD) which measures changes in X-ray absorption coefficients under different circular polarizations. By detecting these parameter changes in X-ray transmittance, the system achieves high-precision magnetic property measurements that overcome conventional detection limitations
2Length of stationary object
If conventional electron beam methods are used, then surface magnetic characteristics can be observed, but observation depth is limited to several nanometers due to electron penetration depth
Solution Approach 1:
The patent substitutes electron beam methods with X-ray irradiation. X-rays have significantly greater penetration depth than electrons, enabling observation of magnetic properties throughout the bulk sample while maintaining measurement precision through XMCD techniques
3Measurement precision
If conventional surface observation methods are used, then surface magnetic characteristics can be measured, but results are affected by oxidized layers on the sample surface
Solution Approach 1:
The patent replaces surface-sensitive electron beam detection with X-ray transmission detection. Since X-rays penetrate through the sample, the measurement reflects bulk magnetic properties rather than being dominated by surface oxidized layers, thereby eliminating this harmful interference
Solution Approach 2:
The patent uses transmitted X-rays as an intermediary to probe bulk magnetic properties. The X-rays pass through the sample without being significantly affected by surface oxidized layers, providing accurate information about the true magnetic characteristics of the bulk material
4Measurement precision
If conventional methods are used to observe magnetic samples within external magnetic fields, then magnetic domain imaging can be achieved, but measurement accuracy is compromised due to interference from the external magnetic field
Solution Approach 1:
The patent substitutes electron beam detection with X-ray detection based on XMCD. This substitution enables accurate measurement of magnetic structures within external magnetic fields because X-ray transmission is not influenced by the external magnetic field, eliminating the interference problem
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
Enables high-sensitive and precise measurement of magnetic sensitivity and structure of bulk samples, allowing for the characterization of single crystal grains with thicknesses between 50 nm and 1000 nm, overcoming previous limitations in depth and accuracy.
Implementation Method 1
Avalanche photodiode to measure photo-count of X-ray transmittance
Implementation Method 2
intensity of transmission X-ray passing the sample is changed in accordance with whether the external magnetic field direction is parallel or anti-parallel to the polarization light direction
Implementation Method 3
a magnetic sample is placed in the external strong magnetic field, an internal magnetization direction of the magnetic sample is aligned with one direction
Data Source
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AI summary
The object of the present invention is to provide a method, system and apparatus that are capable of measuring magnetic characteristic of crystal grains composing magnetic polycrystalline materials in the magnetic field or nonmagnetic field by X-ray magnetic circular dichroism. In particular, the present invention is capable of measuring the magnetic characteristic of comparatively very thick materials having a thickness in the range from 50 to 1000 nm and prepared by fabricating microtome sections using focused ion beam etching.