Recent advances in XRF in diamonds focus on using high-resolution, synchrotron-based techniques for trace element analysis, chemical state analysis of impurities, and identifying synthetic diamonds. Developments include using XRF with other techniques like X-ray absorption spectroscopy (XAS) for more complete analysis and using nanoprobes for spatial resolution down to 50 nm. Researchers are also creating methods to analyze trace elements in synthetic diamonds with high precision, sometimes achieving concentrations far greater than in natural diamonds.  

Key advancements

• High-resolution spatial mapping: 

Synchrotron XRF, especially with nanoprobe techniques, provides nanoscale mapping of elemental distributions within a diamond, revealing the relationship between elements and growth sectors. 

• Chemical state analysis: 

Using techniques like XANES (X-ray Absorption Near Edge Structure) spectroscopy alongside XRF, researchers can determine the chemical state and site of impurities within the diamond lattice (e.g., the location of nickel atoms). 

• Analysis of synthetic diamonds: 

XRF is crucial for characterizing synthetic diamonds, including:

• Trace element analysis: Detecting and quantifying trace impurities (like Co and Mn) incorporated from metallic solvents used during synthesis. 
• Synthetic vs. natural identification: Identifying synthetic diamonds based on their trace element composition, which differs from natural diamonds. 
• Detecting intentional doping: Synthesizing and analyzing diamonds with specific doped atoms, like Europium (Eu), to achieve high concentrations (e.g., 51 ± 5 ppm) for specific properties. 
• Integration with other techniques: 

XRF is increasingly combined with other techniques like X-ray diffraction (XRD) and XAS to provide more comprehensive elemental and structural information about the sample. 

• Gemological applications: 

In the gemological industry, XRF is used to distinguish natural from synthetic diamonds and to detect treatments like fracture filling by showing the elemental composition of the filling agents.