Survey Spectra in X‑ray Photoelectron Spectroscopy (XPS) Explained: First Step Every Analyst Needs
What is Survey Spectra in XPS?
Purpose of Survey Spectra
- The main purpose of survey spectra in X-ray Photoelectron Spectroscopy (XPS) is to identify the types of elements present in a sample.
- Survey spectra are crucial when the elemental composition of a sample is unknown, such as identifying elements like lead, cobalt, oxygen, or zinc.
Characteristics and Importance
- Survey spectra serve as a critical first step for element identification and provide a quick overview of the elements on the sample surface.
- It is often referred to as "wide scan" due to its broad energy range and low resolution compared to high-resolution spectra.
Qualitative Analysis
- The analysis performed using survey spectra is qualitative; it focuses on identifying elemental symbols rather than quantifying their amounts.
- The energy range used in survey spectra includes two sources: aluminum and magnesium, which contribute to its wide scanning capability.
Key Steps Involved in Survey Spectra
Step-by-Step Process
- Step 1: Mark the peaks observed in the survey spectrum. Peaks correspond to different binding energies.
- Step 2: Identify these peaks with their corresponding core level binding energies.
Comparison with Binding Energy Tables
- Step 3: Compare identified binding energies from Step 2 with established binding energy tables available online, excluding helium and hydrogen.
Element Identification
- Step 4: After comparing values from the binding energy table, identify which elements correspond to each peak based on their known binding energies.