X-RAY DIFFRACTION TAUGHT AS A ONE-HOUR SUPPLEMENT TO A TRADITIONAL MINERALOGY COURSE

The geology program (B.S. Geology) at UTC has recently begun integrating x-ray diffraction (XRD) back into its curriculum. The program's powder diffractometer, funded by the National Science Foundation (NSF DUE-9952345) and UTC's Center of Excellence for Computer Applications (CECA), was commissioned in June 2001. It replaced an obsolete instrument that lacked automation and modern safety devices.

At UTC, Mineralogy is required of geology students during their sophomore year. A 1-hour supplement to Mineralogy, X-ray Diffraction Methods, was first taught during the Fall of 2001 to accommodate student use of the instrument and to offer a more thorough treatment of X-ray crystallography than was previously taught. Production and detection of X-rays, safety considerations, and principles of powder diffraction are taught by traditional lecture-based instruction. Students then use the diffractometer for routine phase identification, using both manual and computer-automated procedures. To better understand the instrument, students perform experiments that test the effects of optical components and specimen displacement. Other exercises, such as determining the dimension of an isometric unit cell and how lattice parameters relate to simple ionic substitution, serve to improve students' understanding of crystal structure.

Once versed with the instrument, students are given freedom to analyze other crystalline substances of their choice. Analyses of pharmaceuticals, construction materials, and other household products, done in response to students' interests, demonstrate the power of XRD as an analytical tool and, in some cases, reinforce the practical importance of minerals. (In one case, a student analyzed his own gallstones.)

It is anticipated that the sophomore experience with XRD will promote elective student use of the instrument in upper-level courses that integrate research, such as Sedimentary Rocks and Stratigraphy, Petrology, Sedimentary Petrology, and Research (Senior Thesis).

The class of 2004 will include the first students to have taken the X-ray methods class. Early indications are that these students will have a better understanding of crystal structure and X-ray diffraction and will have gained valuable research experience for having used the XRD.