Woo hoo!! Got to work with the X'Pert Pro for X-Ray reflectivity

On Monday, we worked with a very interesting instrument. Its the X'Pert Pro and it used x-rays to measure the thickness of the films. We read a few articles online to familiarize ourselves with the process. One of the articles gives a very good explanation on how it works. Lots of math but the software in the X'Pert Pro does it for you. Here is a picture or check out more pictures by clicking the link on top right section of the Blog.



We can't use a simple device like a ruler or a Vernier caliper to measure the thickness of the film. Those can only measure in the centimeter or millimeter scale and they could damage the film. Since the film is in the nanometer range, billionth of a meter, we need something much more precise. X-ray reflectivity works on the concept of the reflection of the x-rays by the film and by the glass slide the film is on. By comparing the reflections from both materials, we are able to calculate the thickness of the films we are working on, which are between 88 to 95 nm thick.
We first had to set up the X'Pert to analyze using x-ray reflectivity. This is because it can be used for several other x-ray analysis. Once the correct components have been set up, the instrument must be calibrated to analyze the slide with the film. Jiangshui went through quite a few instructions since we will be doing the analysis ourselves later. I won't go through the steps but just know the instrument is set to analyze the film by x-ray reflectivity, the angles must be set for precise measurements, and it must be set to a "blank" before starting the analysis. Once set, the slide is placed in the X'Pert Pro and set up for the thickness of the slide and it runs for 1.5 hours, going through different angles of reflection. When it is done, the graph is analyzed for certain crests and troughs. This is what is used to give us the final thickness of the film. The film, at least today, came out to 86 nm.