Introduction to Powder X-ray Diffraction
Submitted by Maggie Geselbracht, Reed College
This quick lab experiment is designed to introduce students to powder X-ray diffraction including sample preparation, data collection, and the analysis of diffraction data to refine lattice parameters. Diffraction data is collected for a sample of the cubic perovskite SrTiO3 (useful data can be obtained in relatively short times) and compared to data collected previously (over 6 hours) for the orthorhombic perovskite CaTiO3. Students index the diffraction pattern of SrTiO3 by comparison to the JCPDS database, and use a free program, UnitCell, to refine the lattice parameter.
This lab experiment typically follows the Optical Transform experiment simulating X-ray diffraction and introduces students to the powder diffractometer, data collection and analysis, and the UnitCell program, which may be used in a subsequent experiment. The UnitCell program can be somewhat buggy, particularly the PC version. But it is a very helpful (and free!) program.
1 hour lab time, 1 hour for analysis