DELMIC Microscopy Blog

Studying formation of sedimentary rocks, observing changes in the chemical composition of zircons, and understanding underlying causes for luminescence of sapphires: all of these are possible with one versatile technique. Cathodoluminescence (CL) is a very useful method of data acquisition in geosciences as it reveals information not readily provided by other techniques.

The excitation of electrons in the sample that produces the light seen through a cathodoluminescence system occurs in specific chemical impurities or intrinsic defects within a geological structure.

One of the applications of cathodoluminescence is studying optical nanoantennas. But what are they exactly? These devices, made usually from noble metals (gold or silver, for example) or from semiconductor materials, are capable of amplifying and manipulating light on the nanoscale.
Dr. Ruggero Verre is one the Delmic’s oldest customers: he is a post-doctoral researcher in the Department of Applied Physics at the Chalmers University of Technology in Gothenburg, Sweden. Optical nanoantennas is the focus of his research group, headed by Prof. Mikael Käll.

One way to study the properties of the antennas and understand how they work is by characterizing them with cathodoluminescence. The group of Ruggero Verre has been using the SPARC cathodoluminescence detector to study them, and they have achieved some interesting results.

What is a time-resolved cathodoluminescence? How can it be applied in different fields? In the new video Toon Coenen, application specialist at Delmic, gives an explanation of this imaging technique.

In this short video about the SPARC our application specialist Toon Coenen talks about the main three advantages of this cathodoluminescence system. What are the possibilies of the SPARC and why cathodoluminescence is gaining poplarity in various scientific fields? Find out from the video!

Characterization at the nanoscale is becoming increasingly important as new discoveries are made and structures are developed at smaller scales. Optical characterization alone is not sufficient to study materials at a scale smaller than the wavelength of light, and electron microscopy results in limited data. This is an issue faced by scientists in fields ranging from materials science to the geosciences. 

This is why DELMIC has developed the SPARC cathodoluminescence (CL) system, which is designed to fit on a scanning electron microscope and detect CL emission using any of available five imaging modes. The SPARC is unmatched in terms of its unique features and high performance, and is recommended for any researcher that wants to keep pace with the competitive scientific community.

Those who understand the basic mechanisms of cathodoluminescence (CL) know that it is essentially a useful byproduct of electron microscopy. Fast electrons that are fired at a material cause it to become excited, thereby emitting photons of characteristic wavelengths. CL intensity measurement is one of the many useful methods using CL emission to obtain valuable information about your sample complementary to other techniques such as SE, BSE, EBSD or EDS.

This article further explains how CL intensity mapping exactly works and how it can be employed in various types of research.

In 1897, the electron was discovered by Sir Joseph John Thomson. The physicist and eventual Nobel Prize winner was in fact conducting research on “cathode rays”. At the time, cathode rays were only known as the consequence of an electric current that was passed through a vacuum tube. It was observed that electrically charged particles would collide with atoms at the end of the tube and excite them, thus causing them to fluoresce, or emit fluorescent light. It was further made evident that these were rays travelling in a straight line from one end of the tube to the next, by placing a shape in the middle of the tube and observing that very shape casting a shadow at the end of the tube.