X-ray Photoelectron Spectroscope Auger Curve Fitting for Transition Metals

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Solution Overview

Problem

Current X-ray photoelectron spectrometers struggle to accurately analyze metals from the fourth or higher period of the periodic table due to the small shift amount of peaks in photoelectron spectra when chemical bonding states change, making it difficult to apply curve fitting processes effectively.

Innovation Solution

The method involves acquiring both photoelectron and X-ray-excited Auger spectra, using an electron beam-excited Auger electron standard spectrum for curve fitting on the Auger spectrum to calculate the quantitative value of each chemical bonding state of the analysis target element, enabling accurate analysis even for metals in the fourth or higher period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If curve fitting process is applied to photoelectron spectrum of transition metals, then quantitative analysis of chemical bonding states is attempted, but the small peak shift amount makes the curve fitting inappropriate and inaccurate

Engineering Contradiction:
Improvequantitative analysis accuracy of chemical bonding statesVSAvoidapplicability of curve fitting process
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary approach by using a database of reference Auger electron spectra corresponding to various chemical bonding states. Instead of directly applying curve fitting to the problematic photoelectron spectrum, the method compares the measured Auger spectrum against stored reference spectra to identify and quantify chemical bonding states, thereby mediating the analysis process to achieve accurate results for transition metals

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the analytical parameter from photoelectron spectrum peak position (which has small shifts for transition metals) to Auger electron spectrum parameters. By measuring and analyzing Auger electron kinetic energies and intensities instead of photoelectron binding energies, the method achieves sufficient spectral feature differentiation for accurate chemical bonding state analysis of transition metals

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If photoelectron spectrum analysis is used for light elements, then curve fitting with mixed Gaussian/Lorentzian function provides accurate results, but this method cannot be appropriately applied to transition metals

Engineering Contradiction:
Improvecurve fitting accuracyVSAvoidapplicability to different element types
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal analysis method that works for all element types including transition metals. By using Auger electron spectroscopy with a database of reference spectra, the system achieves multi-functionality - it can analyze light elements, transition metals, and other materials with a single unified approach, eliminating the need for element-specific analysis methods

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces an intermediary approach by using a database of reference Auger electron spectra corresponding to various chemical bonding states. Instead of directly applying curve fitting to the problematic photoelectron spectrum, the method compares the measured Auger spectrum against stored reference spectra to identify and quantify chemical bonding states, thereby mediating the analysis process to achieve accurate results for transition metals

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows for precise calculation of the quantitative value of analysis target elements in each chemical bonding state, overcoming the limitations of peak shift and complexity in the Auger spectra of transition metals, thereby enhancing analysis accuracy.

Implementation Method 1

photoelectrons emitted from a specimen upon irradiation with X-rays

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

Auger electrons emitted from a specimen by irradiating the specimen with X-rays

Methodology Applied
Scientific EffectAuger effect: Auger Effect

Data Source

PatentEP3139158B1Analysis method and x-ray photoelectron spectroscope
Publication Date: 2021.03.03 JEOL LTD
  • EP3139158B1 patent drawingFigure 1
  • EP3139158B1 patent drawingFigure 2~3
  • EP3139158B1 patent drawingFigure 4~5

AI summary

An analysis method includes: acquiring a photoelectron spectrum and an X-ray-excited Auger spectrum, the photoelectron spectrum being obtained by detecting photoelectrons emitted from a specimen (S) by irradiating the specimen with X-rays, and the X-ray-excited Auger spectrum being obtained by detecting Auger electrons emitted from the specimen (S) by irradiating the specimen (S) with X-rays; calculating a quantitative value of each element included in the specimen (S) based on the photoelectron spectrum; and performing a curve fitting process on the X-ray-excited Auger spectrum by using an electron beam-excited Auger electron standard spectrum, and calculating a quantitative value of an analysis target element in each chemical bonding state included in the specimen (S).