ESCA analysis, also known as Electron Spectroscopy for Chemical Analysis or X-Ray Photoelectron Spectroscopy (XPS), is an incredibly useful surface analysis technique that provides elemental and binding energy information about a material’s surfaces and interfaces. In fact, ESCA analysis can detect all elements from lithium to uranium with detection limits of ca. 0.1 atomic percent.
How Does It Work?
What is ESCA Analysis and How Does It Work?
ESCA analysis uses an x-ray beam to excite atoms on the surface of a solid sample, which results in the emission of photoelectrons. Then, an energy analysis of the photoelectrons is performed to identify both elemental and chemical bonding information.
The ESCA analysis process can be broken down into three parts:
- The survey scan, which identifies the elemental composition of the sample surface.
- The high-resolution multiplex scan, which measures the atomic concentrations of the elements identified in the survey scan (Note: H and He cannot be detected). Detection limits are approximately 0.1 atom percent for most elements. Also measures the chemical environment of each element through its binding energies. Precise determination of binding energies are made through the use of curve-fitting routines. A NIST database is available for identifying binding energies with actual compounds.
- The depth profile, which measures the distribution of elements as a function of depth into the sample. Depth resolution is dependent upon sample and sputtering parameters (ca. 100 Å resolution is not unusual). Typical sputtering rate is 30 Å/min.
Learn how ESCA analysis helped identify a contaminant on a plastic part.
Applications & Industries
ESCA Analysis Applications & Industries
- General manufacturing
- Medical device manufacturing
- Polymers and plastics
- Electronics and hard drive manufacturing
- Evaluating the passivation of stainless steels and the oxidation of chromium and iron.
- Studying the surface chemistry of polymers, glasses and other insulators.
- Resolving issues related to metal interdiffusion, resin-to-metal adhesion and oxidation.
Read how Innovatech Labs has used ESCA for stainless steel passivation analysis.
ESCA Analysis Sample Requirements
- Sample type: Samples for ESCA (XPS) can be conductive or non-conductive materials.
- Sample size: The sample cannot exceed 1″ (25 mm) in any lateral direction, and height should not exceed ½” (12 mm).
- Sample compatibility: The sample must be compatible with high vacuum environment (ca. 1×10-9 Torr).
- The typical analysis time ½ hour per sample. However, depth profiles may take longer depending on the total depth being sputtered.
- Reproducibility has a 10% relative error (i.e. estimated error in repeated analyses) and a 20% absolute error (i.e. error between analysis and known standard).
- The minimum area of analysis is 200 mm.
- Angular resolved measurements are available with takeoff angles from 10º to 80º.
- Standard and monochromatic X-ray sources are available.
Contact Innovatech Labs for ESCA Analysis
Innovatech Labs provides prompt service on all ESCA analysis samples. In fact, most samples can be analyzed in five or fewer business days. Contact us today for more information about ESCA analysis.