A Critical Factor When Obtaining X-Ray Microanalysis Data

Clients are careful; they want to understand the data in hand before they begin devising a solution(s) to their materials issues. Scientists at McCrone Associates help guide clients through the analytical process, which typically involves an approach using several analytical methods to help ‘tease out’ the probable cause of the issue. To determine the most effective analytical approach, factors that affect the collection and outcome of the data must be considered. One example is the consideration of sample geometry and morphology.

During recent advanced SEM courses at Hooke College of Applied Sciences factors affecting the collection of X-ray microanalysis data, including sample geometry and surface morphology, were demonstrated through a variety of hands-on microanalysis exercises prepared by instructors Dr. Debra L. Joslin and Dr. Craig S. Schwandt, both senior research scientists at McCrone Associates, Inc.

Knowledge of sample geometry/morphology is critical to obtaining accurate and meaningful X-ray microanalysis data. An X-ray mapping exercise of a heterogeneous sample containing mercury serendipitously provided an outstanding example of the effect of sample geometry on X-ray absorption and X-ray intensities. The false colors in the image show the heterogeneity of the sample. Relative to the sample, the X-ray detector was positioned to the upper left hand side. Portions of the sample that contained more topography and had a high atomic number, such as mercury, absorbed many of the X-rays and produced a shadowing effect. This exercise demonstrates the importance of sample shape and preparation and how these factors influence analytical results.

Do you need a solution for your materials issue, or have questions about an analytical method? Scientists at McCrone Associates can help via direct phone conversation, email descriptions, and education during one of the courses offered through Hooke College of Applied Sciences.