JEOL USA blog

High Speed Milling for Rapid Cross-Section Polishing

Fri, 05 Jun 2026 11:21:58 GMT

Where Do Silicon Drift Detectors Fit into EDS?

Wed, 20 May 2026 12:05:09 GMT

What Is Surface Analysis?

Tue, 20 Jan 2026 00:53:09 GMT

When to Choose EDS Analysis Over EELS?

Wed, 11 Sep 2024 18:16:00 GMT

When to Choose EDS Analysis Over EELS?

In materials science and electron microscopy, choosing between energy-dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS) can significantly impact the quality and type of data obtained. Understanding the strengths and limitations of each technique is crucial for making informed decisions. Below we delve into the key factors influencing the selection of EDS or EELS.

Detailing EDS and EELS

The ability to understand a material's elemental composition is a similarity that EDS analysis and EELS share. However, they are different techniques. Here is an overview of EELS and EDS:

EDS: When a sample and electron beam come into contact, the sample's atoms emit inner-shell electrons. These leave behind spaces that are filled by outer-shell electrons. While these electrons transition into the space, they give off energy, which are seen as X-rays. The characteristic X-rays can be attributed back to different elements. They are evaluated through an EDS detector by examining their energies
EELS: When an electron beam, one with its kinetic energy defined, meets a sample, inelastic scattering occurs and the electrons’ energy becomes lower. An electron spectrometer can study this energy reduction to determine the sample's make-up.

Comparing EDS to EELs

1. Elemental Range

When considering elemental range, EDS and EELS have distinct preferences. EDS is generally more effective for heavier elements with atomic numbers greater than 11. This is due to the nature of X-ray emissions. They become more prominent and easier to detect as the atomic number increases. Conversely, EELS excels in detecting lighter elements, particularly those with atomic numbers less than 30. As a result, EELS is particularly suitable for studying light elements such as carbon, nitrogen, and oxygen, which are critical in organic and biological materials.

2. Spatial Resolution

Spatial resolution is a crucial factor, especially in nanomaterials research. EELS typically offers superior spatial resolution compared to EDS. This advantage arises from the ability of EELS to analyze fine structures and interfaces at the atomic scale. For instance, when studying the atomic arrangements in nanowires or the interfaces in thin films, EELS provides unparalleled detail that is essential for understanding material properties at the nanoscale.

3. Chemical State Information

EELS stands out for its ability to provide detailed information about the chemical bonding and electronic structure of elements. This capability is invaluable in fields such as materials science and semiconductor research, where understanding the chemical state and electronic transitions is crucial. EELS can reveal subtle changes in bonding and the electronic structure. Moreover, it can offer insights into the material's behavior under different conditions.

4. Sample Thickness

The choice between EDS and EELS is also influenced by sample thickness. EDS can handle thicker samples effectively, making it suitable for bulk materials. On the other hand, EELS requires thin specimens, typically under 100 nm, to avoid complications from multiple scattering events. This limitation makes sample preparation more challenging for EELS. However it does allow for the high-resolution analysis of thin films and nanostructures.

5. Quantification

For straightforward compositional analysis, EDS often has the upper hand. EDS is easier to quantify and provides reliable compositional data for bulk samples. Its user-friendly nature and robust quantification capabilities make it a go-to method for routine analysis, particularly in industrial applications where rapid and accurate results are necessary.

6. Energy Resolution

When it comes to energy resolution, EELS, especially with monochromated systems, surpasses EDS. The superior energy resolution of EELS helps detect fine structure details and subtle chemical changes that EDS might miss. This high energy resolution is essential for investigating electronic transitions and fine details in material spectra.

7. Time and Expertise

The practical aspects of time and expertise cannot be overlooked. EDS analysis is generally faster and requires less specialized expertise to interpret. This makes EDS more suitable for high-throughput applications and routine analysis where time efficiency is paramount. In contrast, EELS, with its complex data and higher resolution, often demands more time and expertise to interpret the results.

Integrative Approach

In practice, the choice between EDS and EELS is not always mutually exclusive. Many modern electron microscopes are equipped with both EDS and EELS capabilities. This can allow researchers to leverage the strengths of both techniques for a comprehensive analysis. For example, combining EDS for elemental mapping with EELS for detailed chemical state analysis can provide a holistic understanding of the material under investigation.

Which Will You Try, EDS OR EELS?

The decision to use EDS or EELS hinges on several factors, including elemental range, spatial resolution, chemical state information, sample thickness, quantification, energy resolution, and the practicalities of time and expertise. By carefully considering these factors, researchers can choose the most appropriate technique for their specific needs. No matter which tool you use, we, JEOL USA, will be here to support your decision by delivering you quality products, for instance our Monochromated ARM200F for EELS, or robust insights from our electron optic documents, news magazine, and news page. We have a wealth of information waiting for you, from details about how our microscopes can be used for failure analysis to articles on whether EDS data can be trusted. Explore our website and see what you can find, be it instruments or knowledge, that will improve your experiments.

A Quick Guide to EDS Elemental Analysis

Tue, 27 Aug 2024 20:16:00 GMT

How to Decipher an SEM-EDS Spectrum

Thu, 08 Aug 2024 16:03:40 GMT

How to Decipher an SEM-EDS Spectrum

Investigating the chemical composition of materials is important for fully understanding their material properties. Often, chemical heterogeneity at the micro- to nanoscale influences the macroscopic behavior of materials. For these types of samples, SEM-EDS is ideal.

Scanning Electron Microscopy (SEM) can be used in tandem with Energy Dispersive X-ray Spectroscopy (EDS) to better understand material properties. At its core, SEM uses a high-energy electron beam to characterize samples at the micro- to nanoscale, offering higher resolution and depth of field than other microscopy techniques. Secondary and backscattered electrons generated by interactions between the electron beam and sample can be used to characterize surface morphology and composition respectively. Similarly, characteristic X-rays generated by the sample can be analyzed to assess its composition.

Characteristic X-rays are emitted when outer orbital electrons within an atom relax to fill lower-energy vacancies within inner orbitals created by a high-energy source such as an electron beam. Both the energy and wavelength of these X-rays are unique to the element they are generated from. While multiple techniques exist to analyze these X-rays, perhaps the most common to pair with SEM is EDS. At their core, EDS detectors analyze the chemical composition of materials by counting the X-rays being generated and measuring each X-ray’s energy to determine what element it came from.

EDS detectors are prized for their speed, versatility and ease of use. They allow users to quickly assess what elements are present in a sample and estimate the relative abundances, often in near-real time and without destroying the sample. We often visualize EDS data as a spectrum, showing X-ray energy vs. number of X-rays analyzed (intensity). Interpreting this spectrum and how it is transposed into chemical compositions is critical for accurately characterizing materials.

Although technologic advancements such as automatic element identification, peak deconvolution and quantification have vastly simplified interpreting EDS data, it is still important to understand the principles and best practices of SEM-EDS. This basic understanding empowers users to feel confident about their SEM-EDS results and consistently collect the best chemical data possible.

Read on to learn more detail about how to interpret and utilize an SEM-EDS spectrum.

1. Identifying the Elements Present

When irradiated by a high-energy source such as an electron beam, every element emits a set of X-rays with unique energies and wavelengths, hence, “characteristic X-rays”. Modern state-of-the-art SEM-EDS detectors can analyze X-rays ranging in energy from tens of electron volts (eV) to tens of kiloelectron volts (keV), allowing users to characterize nearly every element between Li and U. Most standard EDS systems are optimized for analyzing Be or B through U.

As shown in Figure 1 below, we visualize EDS data as a spectrum, plotting X-ray energy versus intensity. The peak intensity corresponds to the element’s relative abundance in the sample, while the width of each peak corresponds to the energy resolution of the EDS detector, typically 125-132 eV (FWHM at Mn-Kα).

Modern SEM-EDS software is designed to automatically identify X-ray peaks by comparing their shape and energy to a known database. This allows users of all skill levels to readily collect EDS data. However, for minor or trace (~0.1-5 wt%) elements, the software may be unable to distinguish the peak from the background radiation (Bremsstrahlung). In this case, users may need to manually examine the spectrum to confirm the element's presence. Similarly, some X-ray peaks overlap within the uncertainty of the method, requiring software peak deconvolution. While this method is robust for even severe peak overlaps (e.g., Ti-Ba or W-Si), users should be aware of what peak overlaps to expect for their sample to ensure they are adequately accounted for.

2. Quantitative Analysis

SEM-EDS is used both for providing qualitative information about the elements present and as a semi-quantitative analysis technique. To accurately quantify elemental concentrations, considerations such as the homogeneity, thickness, and surface topography of the sample are essential. These factors influence the accuracy of the quantitative results.

While there are multiple approaches for calculating the sample composition from an EDS spectrum, the simplest and most widely utilized is standardless quantitative analysis. This method compares the relative intensities of all of the identified peaks, normalizing the results to 100%. A matrix correction (e.g., ZAF, Φρz) is applied to account for variations in X-ray yield efficiency as a function of composition. For an ideal sample, this method is reproducible within ±2% to ±5% for major components.

Alternatively, some users may choose to calculate quantitative results using standards. In this case, the peak intensity of each element present in the sample is compared to that of a standard. A matrix correction is still applied. While this approach in principle yields more accurate quantitative results, it relies more heavily on ideal sample preparation and is far more susceptible to user error.

3. Sample Preparation

The quality of SEM-EDS analysis is highly dependent on sample preparation. The sample should be polished, flat, and homogeneous relative to the interaction volume of the electron beam to ensure accurate chemical analysis. For samples with non-uniform composition, acquiring spectra from multiple areas or acquiring a hyperspectral EDS map can help assess heterogeneity.The quality of SEM-EDS analysis is highly dependent on sample preparation. The sample should be polished, flat, and homogeneous relative to the interaction volume of the electron beam to ensure accurate chemical analysis. For samples with non-uniform composition, acquiring spectra from multiple areas or acquiring a hyperspectral EDS map can help assess heterogeneity.

4. Consideration of Topography

The topography of a sample can significantly affect SEM-EDS analysis. Rough or irregular surfaces may preferentially absorb or block X-rays, leading to errors in calculated composition. Positioning the sample to provide a direct line of sight between the region of interest is crucial and can assist in fully characterizing the sample, though quantitative results should be treated with caution.

5. Accelerating Voltage

The choice of accelerating voltage is critical for the excitation of X-ray lines of elements in the sample. A voltage 1.5 to 2 times higher than the energy of the X-ray lines from the element(s) of interest is recommended to efficiently excite the element. For unknown samples, using an accelerating voltage between 15 kV and 20 kV ensures that all elements present are identified. However, users might choose to collect EDS data at lower accelerating voltages to minimize interaction volume, especially to aid in characterization of small nano- to micro-scale features.

6. Hyperspectral EDS Mapping

Modern EDS systems offer advanced features like acquiring hyperspectral EDS maps, enabling the detailed characterization of chemically heterogeneous samples. Rather than acquiring an EDS spectrum at a single point, hyperspectral maps are more akin to SEM images, where every pixel in the image represents an individual EDS spectrum. This technique is powerful for understanding the distribution of elements in a sample, allowing identification and full characterization of discrete layers, phases or chemical gradients. The ability to treat each pixel as a quantitative analysis by leveraging quantitative mapping (QMap) allows samples even with complex matrices to be studied. This makes the technique invaluable for studying samples with:

● Complex compositions

● Overlapping peaks

● Minor/trace elements with low peak/background ratios

Final Thoughts on the SEM-EDS Spectrum

With a basic understanding of the principles of SEM-EDS, researchers and analysts can effectively acquire and interpret robust EDS data. This can unlock valuable quantitative and qualitative insights into their samples.

It is crucial to consider the limitations and challenges associated with SEM-EDS analysis, including sample preparation and the potential for quantitative errors. However, with a careful approach and interpretation, SEM-EDS remains an indispensable tool in materials science and engineering for elemental analysis at the micro- to nano scale.

JEOL USA’s Tools Incorporate the SEM-EDS Spectrum

SEM-EDS analyses are fast, effective, and can help interrogate a wide range of material properties and characteristics. Understanding what EDS spectra are and how they can be used to inform qualitative and semi-quantitative chemical analysis of samples is essential for accurately interpreting and gaining the most out of this type of analysis.

SEM-EDS can provide powerful information about the material properties at the micro- to nanoscale. It is therefore utilized for with a variety of materials such as:

● Polymers

● Metals

● Ceramics

● Composites

● Batteries

● Pharmaceuticals

● Rocks and minerals

● Forensics

● Electronics and semiconductors

Chemical analysis of these materials by SEM-EDS can be leveraged across industry, government and academic sectors for wide range of applications spanning from investigating the chemical composition of minerals in meteorites to fingerprinting forensic samples to developing next-generation energy storage solutions and beyond.

If you are looking for an innovative SEM-EDS tool or analytical technique to help you with your research, we, JEOL USA, would recommend browsing our website.

Ready to learn more about our Gather-X Windowless EDS? This state-of-the-art detector can help you characterize ultra-low energy characteristic X-rays that are under 1 keV, including Li-Kα. When paired with our ultrahigh resolution field emission SEM product line, this ground-breaking technique is transforming the types of materials that we can observe and study.

For more information on SEM-EDS analysis or the SEM-EDS spectrum, we invite you to browse through our website. Check out our blog page to learn more about elemental analysis with electron microscopes, a guide on energy dispersive spectroscopy and so much more!

Our technology can help you ensure that your materials have the right characteristics for their future applications. Contact us today to find the best SEM-EDS tool for you.

Why Use EDS Analysis for Li-Ion Batteries?

Sun, 14 Jul 2024 15:32:00 GMT

Why Use EDS Analysis for Li-Ion Batteries?

Before lithium-ion (Li-ion) battery commercialization, and subsequent domination of the energy storage market, rechargeable battery chemistries were fraught with limitations. Low energy density, memory effects, high self-discharge rates, and toxicity issues were commonplace. Li-ion batteries, by contrast, delivered higher voltages (around 3.6V per cell). They also offered low self-discharge, rapid charging capabilities, and reduced maintenance. These properties ensured the quick adoption of Li-ion chemistries in portable technologies, fuelling enormous growth through the 1990s. Some experts credit the technology as the foundation of wireless tech. Now, Li-ion batteries are ubiquitous in modern society, and demand is ever-growing.

This growth in demand presents a constant need to optimize performance, safety, and longevity. One technique for achieving these improvements is energy-dispersive X-ray spectroscopy (EDS) analysis. Our blog post delves into why EDS analysis is indispensable for Li-ion battery research and development.

Non-Destructive Elemental Analysis and Mapping

One of the most compelling reasons to use EDS analysis for Li-ion batteries is its ability to perform non-destructive elemental analysis and mapping. EDS can analyze various battery components such as anodes, cathodes, and separator materials.

EDS mapping is instrumental in revealing the distribution and interfaces between different layers and components within a Li-ion battery. Understanding these interfaces is key to enhancing battery performance and longevity. For instance, the interface between the anode and the electrolyte must be well-understood to prevent issues such as dendrite formation, which can cause short circuits and battery failure.

In figure 1, a cross-section of a cathode material was prepared with JEOL’s cross-section polisher. The overall EDS spectrum of the area, individual EDS element maps, and an overlay of these elements is shown.

By providing a detailed elemental map, EDS enables researchers to visualize the distribution of elements and identify any inhomogeneities or defects. This insight is crucial for optimizing the materials and interfaces within the battery, leading to more reliable and efficient energy storage solutions. Additionally, EDS provides this detailed elemental mapping without damaging the sample. The non-destructive nature of EDS ensures that the samples remain intact for further testing and analysis, thereby preserving valuable material and enabling comprehensive studies.

Figure 1: Individual EDS elemental maps, overlay map, and overall EDS spectrum of a cross-section of cathode material.

Correlating Electrochemical Behavior with Microstructural Changes

Another significant advantage of EDS analysis is its ability to be combined with high-resolution imaging in scanning electron microscopy (SEM). This combination allows for the correlation of electrochemical behavior with microstructural changes during charge and discharge cycles. Understanding these correlations is crucial for improving battery performance and addressing issues such as capacity fade and thermal runaway.

High-resolution imaging coupled with EDS provides a comprehensive view of the battery’s microstructure and elemental composition. Researchers can observe how the microstructure evolves over time and how it affects the battery’s electrochemical properties. This holistic approach leads to a deeper understanding of the mechanisms driving battery performance and degradation, paving the way for innovative solutions to enhance battery life and safety.

Air-Isolated Workflow for Sensitive Materials

Lithium oxidizes extremely quickly, making lithium-containing materials a challenge to analyze. Exposure to the atmosphere can alter their composition, leading to inaccurate results. JEOL addresses this issue by offering an air-isolated workflow using a transfer vessel and an inert gas environment for each of our SEMs. This setup prevents atmospheric exposure, allowing for pristine sample analysis.

Figure 2 shows a transfer vessel setup. A sample can be mounted to the sample holder while inside a glove box and then capped with an O-ring seal. The capped sample holder can then be inserted into the specimen exchange chamber of a SEM and the exchange chamber can be evacuated. Once under vacuum, the cap can be removed by screwing the knob assembly into the cap and pulling up. The cap remains in the exchange chamber while the sample is imaged. From there, the sample can be recapped before removing the sample from the SEM.

The air-isolated workflow ensures that sensitive materials remain unaltered during the transfer and analysis processes. This is particularly important for studying materials prone to rapid oxidation or other atmospheric reactions, such as lithium. By maintaining the integrity of the samples, researchers can obtain accurate and reliable data, which is essential for advancing battery technology.

Figure 2: One of JEOL’s air-free transfer solutions. In this case, the sample is mounted to a transfer vessel that is capped in a glove box. The cap is then removed under vacuum in the specimen exchange chamber of the SEM. The sample can be recapped and brought back to the glove box without air exposure.

Detection of Lithium with Windowless EDS

Lithium poses significant challenges for detection and quantification. Firstly, lithium which is bonded to oxygen will not produce many X-rays. Moreover, a standard EDS has a thin polymer or silicon nitride window to protect the silicon drift detector (SDD). This window will absorb very low-energy X-ray signals. Even if Li-containing samples are metallic and kept isolated from the environment, a windowed EDS detector cannot directly detect the characteristic X-rays of lithium (Li-K 54 eV).

Windowless EDS detectors, such as JEOL’s GatherX detector, allow for the detection of ultra-low energy X-rays. These detectors are especially adept at analyzing elements with low atomic numbers like carbon, fluorine, and, critically, lithium, which is why they are crucial for pinpointing the localized chemical makeup of battery components. Lithium’s distribution directly impacts the battery’s performance, efficiency, and safety.

Figure 3 displays an area of a cross-section of a pristine Li metal sample. It shows a sharp Li-K peak, with differences between the inside and the near surface areas of the metal. EDS analysis allows researchers to observe subtle changes in lithium distribution within battery materials. This capability is essential for learning about how lithium migrates during charge and discharge cycles, which in turn helps design batteries with improved charge retention and lifespan.

Figure 3: The area analysis result of a pristine lithium metal cross-section. It shows a sharp Li Ka peak, with differences between the inside and the near-surface areas.

Want to Learn More?

EDS analysis is an indispensable tool for Li-ion battery research and development. Its ability to perform non-destructive elemental analysis and mapping, coupled with high spectral resolution and air-isolated workflows, makes it invaluable for studying battery components and their interactions. By providing detailed insights into the distribution of elements and microstructural changes, EDS enables researchers to design better performing and longer-lasting batteries. As the demand for advanced energy storage solutions continues to grow, the role of EDS in Li-ion battery research will only become more critical.

At JEOL USA, we are committed to advancing the field of lithium-ion battery research with cutting-edge analytical techniques like EDS. Through leveraging our expertise and innovative technologies, researchers can trust the accuracy of their quantitative EDS data, ensuring that every insight leads to tangible improvements in battery performance and safety. Discover more about how our solutions can enhance your research and trust in your quantitative data by visiting our comprehensive guide.

Key Benefits of Air-Isolation for Electron Microscopy

Mon, 01 Jul 2024 15:31:00 GMT

Key Benefits of Air-Isolation for Electron Microscopy

Electron microscopy is an invaluable technique for observing the micro- to nanostructure of a wide range of materials. However, some samples of interest, including catalysts or fuel cells, are reactive to moisture or air. In these cases, it is critical to ensure the materials aren’t exposed to air while transferring them to an electron microscope for imaging and microanalysis. Leveraging an air-isolated workflow enables the direct observation of these materials without degradation. Discover more about the benefits of utilizing air-isolation workflows for electron microscopy below.

Preventing Oxidation and Degradation

Air-isolation in electron microscopy can prevent the oxidation and degradation of air-sensitive samples. Materials like lithium-ion battery components are prone to react with oxygen and moisture in the air. These reactions can alter or destroy the material's structure, making it impossible to accurately characterize their nanostructures. By employing air-isolation systems in electron microscopy, researchers can protect these materials from atmospheric exposure, maintaining their pristine state. This preservation allows for accurate imaging and microanalysis, which is critical for understanding the material's true properties and behavior.

The implications of oxidation and degradation are significant. For instance, lithium, a key component in batteries, is highly reactive with both oxygen and water vapor. Any exposure can lead to the formation of lithium oxides or hydroxides. These can mask the true morphology and chemistry of the sample. Air-isolation systems provide a controlled environment that eliminates such risks, thereby enhancing the reliability of the data obtained from electron microscopy.

Preserving Sample Integrity

Maintaining the original structure and properties of samples is critical for accurate electron microscopy analysis. Air-isolation in electron microscopy can preserve the sample's integrity by preventing artifacts that can arise from air exposure. These artifacts include crumbling, smearing, and distortion, which can compromise the reliability of the data.

For example, the microstructure, crystallography, and layer thicknesses of materials can be significantly altered if exposed to air. Air-isolation systems can maintain the original state of the sample. Therefore, they can ensure that the observed features are true representations of the material. This preservation is crucial for materials research, where understanding the nanostructure of materials can lead to significant technological advancements.

Facilitating Workflow Integration

Air-isolation systems also enhance the workflow integration in materials research laboratories. By enabling the seamless transfer of air-sensitive samples between different instruments, these systems streamline the analytical workflow. For instance, JEOL's air-isolated methodology supports the transfer of samples, using a single holder and transfer vessel, between:

With this integration comes a reduction in the risk of sample contamination and degradation, improving the efficiency and accuracy of the analysis. Researchers can prepare, transfer, and analyze samples under isolated conditions. The separation ensures that the samples remain in their pristine state throughout the entire process. This capability is particularly important in high-throughput research environments where multiple analyses are performed sequentially.

Protecting The Results of Electron Microscopy Devices Through Air-Isolation

The ability to prepare, transfer, and analyze air-sensitive materials under isolated conditions without air exposure is crucial for accurately characterizing their structure and chemistry using electron microscopy techniques. Air-isolation transfer systems in electron microscopy can:

Prevent oxidation and degradation
Enable the analysis of highly reactive materials
Preserve sample integrity
Facilitate seamless workflow integration

As materials science continues to evolve, the importance of air-isolation in electron microscopy will only grow further.

Locate Your Electron Microscopy Equipment at JEOL USA

Maximize the capabilities of your electron microscopy equipment by integrating air-isolation techniques and technologies. Electron microscopy enables the physical and chemical characterization of samples at the micro- to atomic scales, making it a key technology in a wide variety of research sectors.

JEOL USA is proud to offer a selection of scanning electron microscopes and transmission electron microscopes with exclusive options for integrated air isolation transfer to precisely fit your electron microscopy needs. Check out our fully integrated solutions for battery research and development or learn more about how we at JEOL are preparing and analyzing air-sensitive samples using our ion milling systems, state-of-the-art GatherX EDS, and Soft X-ray Emission Spectrometers (SXES).