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XPS Basics: Understanding Survey and High-Resolution Spectra Simplified!
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XPS Basics: Understanding Survey and High-Resolution Spectra Simplified!

Comparison of Survey Spectra and High-Resolution Spectra in XPS Analysis

Overview of Spectra Types

  • The analysis requires both survey spectra and high-resolution spectra to obtain complete information about a sample.
  • Survey spectra provide elemental identification, revealing what types of elements are present in the sample, especially when they are unknown.

Detailed Insights on High-Resolution Spectra

  • High-resolution spectra offer insights into the chemical state, including oxidation states and environmental factors surrounding the elements.
  • In high-resolution spectra, only significant photoelectron peaks or OJ peaks are considered, allowing for clearer differentiation between peaks compared to survey spectra.

Purpose and Analysis Techniques

  • Survey spectra serve as a broad overview (qualitative analysis), focusing on identifying elements without quantifying their amounts.
  • High-resolution spectra provide quantitative data regarding chemical states, enabling detailed analysis of atom quantities based on peak separation.

Resolution Differences

  • The energy range for survey spectra is broader (0 to 14400 eV), while high-resolution focuses on narrower ranges (e.g., 25 to 2045 eV), enhancing detail visibility.
  • Higher resolution allows for better peak separation; this is crucial for understanding spin-orbit separation in high-resolution data.

Peak Convolution and Deconvolution

  • In survey spectra, convolution occurs due to overlapping peaks; deconvolution is not advisable here due to complexity.
  • High-resolution spectra allow for effective deconvolution of convoluted peaks, making it easier to identify distinct features within the data.
Playlists: XPS - X-rays Photoelectron Spectroscopy
Video description

Survey Spectra vs. High Resolution Spectra Both survey spectra & high-resolution spectra are required for a complete a surface analysis of the sample i.e., what elements are present and what are their chemical states. Survey Spectra: It is also called Broad Scan, Broad overview Purpose: Elemental identification & qualitative analysis Energy Range: Broad (focused on all peaks) (0 to 1400 eV) Resolution: Lower and the separation of peaks can not be seen clearly Acquisition Time: Shorter Data: Types of elements only Peak Identification: Peaks corresponding to different elements are identified based on their characteristic binding energies. Surface Contaminants: Common contaminants like carbon (C 1s) and oxygen (O 1s) can be easily identified Relative Abundance: The relative intensities of the peaks can give an approximate indication of the relative amounts of the elements present Deconvolution on a survey spectrum is NOT a good idea. Now let's discuss the other one. High Resolution Spectra: It is also called in-depth overview Purpose: Chemical state analysis and quantitative analysis Energy Range: Narrow (focused on specific peaks) (~ 20 eV) Resolution: Higher Spin orbit separation (Δ) can be seen Acquisition Time: Longer Data: Determines the chemical states and concentrations of the elements. Peak Deconvolution: Detailed analysis can deconvolute overlapping peaks to identify different chemical states (e.g., different oxidation states of the same element) Quantitative Analysis: The areas under the peaks can be used for quantitative analysis to determine the concentration of different chemical states. Chemical Shifts: Small shifts in peak positions can provide insights into the chemical bonding environment and changes in electronic structure Deconvolution is fine on a high-res spectrum Please subscribe to my channel and share it.