EELS

What Is EELS?

EELS measures the energy lost by electrons as they pass through a thin specimen in a TEM. This energy loss corresponds to specific electronic transitions within the material, allowing identification of:

elemental composition
chemical bonding environment
oxidation and valence states
local electronic structure

Because EELS is performed at high spatial resolution, it enables site-specific chemical analysis at nanometer or even sub-nanometer scales.

What EELS Measures

EELS provides detailed information on:

Elemental identification, including light elements such as B, C, N, O, and Li
Chemical bonding and coordination
Oxidation state and valence changes
Electronic structure and local chemistry variations
Composition across interfaces, grain boundaries, and defects

These capabilities make EELS complementary to EDS, especially when light elements or chemical state information is critical.

Why Use EELS?

EELS is selected when conventional techniques cannot fully answer key questions, such as:

Are light elements present, and where are they located?
How does oxidation state change across an interface?
Is there chemical bonding variation at grain boundaries or defects?
What is the chemistry of ultra-thin layers or reaction zones?
How does nanoscale chemistry relate to performance or failure?

EELS provides insight into why materials behave the way they do, not just what elements are present.

Typical Application Scenarios

Interfaces & Thin Films

Chemical analysis across multilayer interfaces
Diffusion and reaction layer characterization
Oxidation or reduction at interfaces

Nanomaterials & Advanced Materials

Chemical state analysis of nanoparticles
Core–shell and gradient structures
Light-element distribution in nanostructures

Semiconductors & Electronic Materials

Dopant and light-element analysis
Interface chemistry in devices
Degradation and reliability studies

Battery & Energy Materials

Local chemistry of electrodes and interfaces
Oxidation state changes during cycling
Light-element behavior (e.g., Li-containing systems)

Failure Analysis

Chemical changes at crack tips or defects
Oxidation, contamination, or reaction products
Comparison of “good vs. failed” regions at the nanoscale

Sample Requirements

EELS requires electron-transparent specimens, typically prepared by methods such as FIB thinning or ion milling. Suitable samples include:

thin films and multilayers
nanoparticles and powders (properly dispersed)
cross-sections of devices or components
interfaces and localized regions of interest

Xinbodi evaluates sample feasibility and preparation strategy based on material type and analytical goals.

What You Will Receive

Each EELS project is delivered with a clear, structured report designed to support technical decision-making. A typical deliverable includes:

project objective and sample description
EELS acquisition conditions and analysis approach
elemental and chemical state spectra
nanoscale chemical maps (when applicable)
comparison across regions, layers, or samples
interpretation linking chemistry to structure and performance
recommendations for follow-up analysis or process optimization

Why Choose Xinbodi for EELS?

Expertise in nanoscale chemical and interface analysis
Integrated TEM-based analytical workflows
Strong experience with light elements and chemical state interpretation
Clear, application-driven reporting
Support for R&D, reliability studies, and failure investigations
Strict confidentiality for proprietary samples and data