Each group of 2 or 3 students will obtain a diffraction pattern for one of three different brasses. The scan should be run over the range 2 = 20-40°, at 2° 2(theta)/min. About 1/2 hr will be required to complete these scans. While the first group is running the diffractometer, the others will explore what a diffraction pattern is and what they think it should look like. As each group obtains its patterns, they will interpret them, and compare with the other patterns. The following equations should be discussed and must be used in the interpretation of the patterns:
(lambda) = 2dhkl sin(thetahkl)
(lambda)alpha = 1.541838 Å
(lambda)beta = 1.392218 Å
(lambda)alpha1 = 1.540562 Å
(lambda)alpha2 = 1.544390 Å
dhkl = a/(h2 + k2 + l2)1/2
During the second week, the interpretation of these patterns will be further explored through discussion and calculations.
After the 2nd week's work, prepare a brief lab report which describes your results, gives final data in tabular form, and contains a relatively lengthy discussion of the concepts which resulted from a consideration of your experimental results. In your report, make sure to use descriptive headings for your discussion, as well as an appropriate title.
Name your file 434lab1.yourlastname (no caps) and email to rx7@mail.psu.edu by midnight, 16 Sept. Any files received that are incorrectly named will be discarded. The only exception is that users of those other computers may have to append .doc to the file name.